LM2575T-ADJ/LF03 - NATIONAL SEMICONDUCTOR

LM1575, LM2575-N, LM2575HV

www.ti.com

SNVS106E –MAY 1999–REVISED APRIL 2013

LM1575/LM2575/LM2575HV SIMPLE SWITCHER

1A Step-Down Voltage Regulator

Check for Samples: LM1575,LM2575-N,LM2575HV

1FEATURES DESCRIPTION

The LM2575 series of regulators are monolithic

23• 3.3V, 5V, 12V, 15V, and Adjustable Output integrated circuits that provide all the active functions

Versions for a step-down (buck) switching regulator, capable of

• Adjustable Version Output Voltage Range, driving a 1A load with excellent line and load

– 1.23V to 37V (57V for HV Version) ±4% regulation. These devices are available in fixed output

voltages of 3.3V, 5V, 12V, 15V, and an adjustable

Max Over output version.

– Line and Load Conditions Requiring a minimum number of external

• Specified 1A Output Current components, these regulators are simple to use and

• Wide Input Voltage Range, 40V up to 60V for include internal frequency compensation and a fixed-

HV Version frequency oscillator.

• Requires Only 4 External Components The LM2575 series offers a high-efficiency

• 52 kHz Fixed Frequency Internal Oscillator replacement for popular three-terminal linear

• TTL Shutdown Capability, Low Power Standby regulators. It substantially reduces the size of the

Mode heat sink, and in many cases no heat sink is

required.

• High Efficiency A standard series of inductors optimized for use with

• Uses Readily Available Standard Inductors the LM2575 are available from several different

• Thermal Shutdown and Current Limit manufacturers. This feature greatly simplifies the

Protection design of switch-mode power supplies.

• P+Product Enhancement Tested Other features include a specified ±4% tolerance on

output voltage within specified input voltages and

APPLICATIONS output load conditions, and ±10% on the oscillator

• Simple High-Efficiency Step-Down (Buck) frequency. External shutdown is included, featuring

Regulator 50 μA (typical) standby current. The output switch

includes cycle-by-cycle current limiting, as well as

• Efficient Pre-Regulator for Linear Regulators thermal shutdown for full protection under fault

• On-Card Switching Regulators conditions.

• Positive to Negative Converter (Buck-Boost)

Typical Application

(Fixed Output Voltage Versions)

Pin numbers are for the TO-220 package.

1Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2SIMPLE SWITCHER is a registered trademark of Texas Instruments.

3All other trademarks are the property of their respective owners.

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.

LM1575, LM2575-N, LM2575HV

SNVS106E –MAY 1999–REVISED APRIL 2013

www.ti.com

Block Diagram and Typical Application

3.3V, R2 = 1.7k

5V, R2 = 3.1k

12V, R2 = 8.84k

15V, R2 = 11.3k

For ADJ. Version

R1 = Open, R2 = 0Ω

Pin numbers are for the TO-220 package.

Figure 1.

Product Folder Links: LM1575 LM2575-N LM2575HV

LM1575, LM2575-N, LM2575HV

www.ti.com

SNVS106E –MAY 1999–REVISED APRIL 2013

Connection Diagrams

(XX indicates output voltage option.)

Top View Top View Side View

Figure 2. Straight Leads Figure 3. Bent, Staggered Leads Figure 4. LM2575T-XX Flow LB03

5-Lead TO-220 Package 5-Lead TO-220 Package LM2575HVT-XX Flow LB03

LM2575T-XX or LM2575HVT-XX See Package Number NDH0005D See Package Number NDH0005D

See Package Number KC0005A

Top View Top View

*No Internal Connection

Figure 5. 16-Lead CDIP and PDIP Packages Figure 6. 24-Lead Surface Mount SOIC Package

LM2575N-XX or LM2575HVN-XX LM2575M-XX or LM2575HVM-XX

LM1575J-XX-QML See Package Number DW0024B

See Package Numbers NFE0016A and NBG

Top View

Figure 7. DDPAK/TO-263 Package

5-Lead Surface-Mount Package

See Package Number KTT0005B

Side View

Figure 8. LM2575S-XX or LM2575HVS-XX

See Package Number KTT0005B

Product Folder Links: LM1575 LM2575-N LM2575HV

LM1575, LM2575-N, LM2575HV

SNVS106E –MAY 1999–REVISED APRIL 2013

www.ti.com

These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam

during storage or handling to prevent electrostatic damage to the MOS gates.

ABSOLUTE MAXIMUM RATINGS (1)(2)(3)

Maximum Supply Voltage LM1575/LM2575 45V

LM2575HV 63V

ON /OFF Pin Input Voltage −0.3V ≤V≤+VIN

Output Voltage to Ground (Steady State) −1V

Power Dissipation Internally Limited

Storage Temperature Range −65°C to +150°C

Maximum Junction Temperature 150°C

Minimum ESD Rating (C = 100 pF, R = 1.5 kΩ) 2 kV

Lead Temperature (Soldering, 10 sec.) 260°C

(1) Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for

which the device is intended to be functional, but do not ensure specific performance limits. For specified specifications and test

conditions, see Electrical Characteristics.

(2) If Military/Aerospace specified devices are required, please contact the TI Sales Office/ Distributors for availability and specifications.

(3) Refer to RETS LM1575J for current revision of military RETS/SMD.

OPERATING RATINGS

Temperature Range LM1575 −55°C ≤TJ≤+150°C

LM2575/LM2575HV −40°C ≤TJ≤+125°C

Supply Voltage LM1575/LM2575 40V

LM2575HV 60V

ELECTRICAL CHARACTERISTICS LM1575-3.3, LM2575-3.3, LM2575HV-3.3

Specifications with standard type face are for TJ= 25°C, and those with boldface type apply over full Operating

Temperature Range .LM2575-3.3

LM1575-3.3 Units

LM2575HV-3.3

Symbol Parameter Conditions Typ (Limits)

Limit (1) Limit (2)

SYSTEM PARAMETERS Test Circuit Figure 25 and Figure 26(3)

VOUT Output Voltage VIN = 12V, ILOAD = 0.2A 3.3 V

Circuit Figure 25 and Figure 26 3.267 3.234 V(Min)

3.333 3.366 V(Max)

VOUT Output Voltage 4.75V ≤VIN ≤40V, 0.2A ≤ILOAD ≤1A 3.3 V

LM1575/LM2575 Circuit Figure 25 and Figure 26 3.200/3.168 3.168/3.135 V(Min)

3.400/3.432 3.432/3.465 V(Max)

VOUT Output Voltage 4.75V ≤VIN ≤60V, 0.2A ≤ILOAD ≤1A 3.3 V

LM2575HV Circuit Figure 25 and Figure 26 3.200/3.168 3.168/3.135 V(Min)

3.416/3.450 3.450/3.482 V(Max)

ηEfficiency VIN = 12V, ILOAD = 1A 75 %

(1) All limits specified at room temperature (standard type face) and at temperature extremes (bold type face). All limits are used to

calculate Average Outgoing Quality Level, and all are 100% production tested.

(2) All limits specified at room temperature (standard type face) and at temperature extremes (bold type face). All room temperature limits

are 100% production tested. All limits at temperature extremes are specified via correlation using standard Statistical Quality Control

(SQC) methods.

(3) External components such as the catch diode, inductor, input and output capacitors can affect switching regulator system performance.

When the LM1575/LM2575 is used as shown in the test circuit Figure 25 and Figure 26, system performance will be as shown in system

parameters of Electrical Characteristics.

Product Folder Links: LM1575 LM2575-N LM2575HV

LM1575, LM2575-N, LM2575HV

www.ti.com

SNVS106E –MAY 1999–REVISED APRIL 2013

ELECTRICAL CHARACTERISTICS LM1575-5.0, LM2575-5.0, LM2575HV-5.0

Specifications with standard type face are for TJ= 25°C, and those with boldface type apply over full Operating

Temperature Range.LM2575-5.0

LM1575-5.0 Units

LM2575HV-5.0

Symbol Parameter Conditions Typ (Limits)

Limit (1) Limit (2)

SYSTEM PARAMETERS Test Circuit Figure 25 and Figure 26(3)

VOUT Output Voltage VIN = 12V, ILOAD = 0.2A 5.0 V

Circuit Figure 25 and Figure 26 4.950 4.900 V(Min)

5.050 5.100 V(Max)

VOUT Output Voltage 0.2A ≤ILOAD ≤1A, 5.0 V

LM1575/LM2575 8V ≤VIN ≤40V 4.850/4.800 4.800/4.750 V(Min)

Circuit Figure 25 and Figure 26 5.150/5.200 5.200/5.250 V(Max)

VOUT Output Voltage 0.2A ≤ILOAD ≤1A, 5.0 V

LM2575HV 8V ≤VIN ≤60V 4.850/4.800 4.800/4.750 V(Min)

Circuit Figure 25 and Figure 26 5.175/5.225 5.225/5.275 V(Max)

ηEfficiency VIN = 12V, ILOAD = 1A 77 %

(1) All limits specified at room temperature (standard type face) and at temperature extremes (bold type face). All limits are used to

calculate Average Outgoing Quality Level, and all are 100% production tested.

(2) All limits specified at room temperature (standard type face) and at temperature extremes (bold type face). All room temperature limits

are 100% production tested. All limits at temperature extremes are specified via correlation using standard Statistical Quality Control

(SQC) methods.

(3) External components such as the catch diode, inductor, input and output capacitors can affect switching regulator system performance.

When the LM1575/LM2575 is used as shown in the test circuit Figure 25 and Figure 26, system performance will be as shown in system

parameters of Electrical Characteristics.

ELECTRICAL CHARACTERISTICS LM1575-12, LM2575-12, LM2575HV-12

Specifications with standard type face are for TJ= 25°C, and those with boldface type apply over full Operating

Temperature Range .LM2575-12

LM1575-12 Units

LM2575HV-12

Symbol Parameter Conditions Typ (Limits)

Limit (1) Limit (2)

SYSTEM PARAMETERS Test Circuit Figure 25 and Figure 26 (3)

VOUT Output Voltage VIN = 25V, ILOAD = 0.2A 12 V

Circuit Figure 25 and Figure 26 11.88 11.76 V(Min)

12.12 12.24 V(Max)

VOUT Output Voltage 0.2A ≤ILOAD ≤1A, 12 V

LM1575/LM2575 15V ≤VIN ≤40V 11.64/11.52 11.52/11.40 V(Min)

Circuit Figure 25 and Figure 26 12.36/12.48 12.48/12.60 V(Max)

VOUT Output Voltage 0.2A ≤ILOAD ≤1A, 12 V

LM2575HV 15V ≤VIN ≤60V 11.64/11.52 11.52/11.40 V(Min)

Circuit Figure 25 and Figure 26 12.42/12.54 12.54/12.66 V(Max)

ηEfficiency VIN = 15V, ILOAD = 1A 88 %

(1) All limits specified at room temperature (standard type face) and at temperature extremes (bold type face). All limits are used to

calculate Average Outgoing Quality Level, and all are 100% production tested.

(2) All limits specified at room temperature (standard type face) and at temperature extremes (bold type face). All room temperature limits

are 100% production tested. All limits at temperature extremes are specified via correlation using standard Statistical Quality Control

(SQC) methods.

(3) External components such as the catch diode, inductor, input and output capacitors can affect switching regulator system performance.

When the LM1575/LM2575 is used as shown in the test circuit Figure 25 and Figure 26, system performance will be as shown in system

parameters of Electrical Characteristics.

Product Folder Links: LM1575 LM2575-N LM2575HV

LM1575, LM2575-N, LM2575HV

SNVS106E –MAY 1999–REVISED APRIL 2013

www.ti.com

ELECTRICAL CHARACTERISTICS LM1575-15, LM2575-15, LM2575HV-15

Specifications with standard type face are for TJ= 25°C, and those with boldface type apply over full Operating

Temperature Range .LM2575-15

LM1575-15 Units

LM2575HV-15

Parameter Conditions Typ (Limits)

Symbol Limit (1) Limit (2)

SYSTEM PARAMETERS Test Circuit Figure 25 and Figure 26(3)

VOUT Output Voltage VIN = 30V, ILOAD = 0.2A 15 V

Circuit Figure 25 and Figure 26 14.85 14.70 V(Min)

15.15 15.30 V(Max)

VOUT Output Voltage 0.2A ≤ILOAD ≤1A, 15 V

LM1575/LM2575 18V ≤VIN ≤40V 14.55/14.40 14.40/14.25 V(Min)

Circuit Figure 25 and Figure 26 15.45/15.60 15.60/15.75 V(Max)

VOUT Output Voltage 0.2A ≤ILOAD ≤1A, 15 V

LM2575HV 18V ≤VIN ≤60V 14.55/14.40 14.40/14.25 V(Min)

Circuit Figure 25 and Figure 26 15.525/15.675 15.68/15.83 V(Max)

ηEfficiency VIN = 18V, ILOAD = 1A 88 %

(1) All limits specified at room temperature (standard type face) and at temperature extremes (bold type face). All limits are used to

calculate Average Outgoing Quality Level, and all are 100% production tested.

(2) All limits specified at room temperature (standard type face) and at temperature extremes (bold type face). All room temperature limits

are 100% production tested. All limits at temperature extremes are specified via correlation using standard Statistical Quality Control

(SQC) methods.

(3) External components such as the catch diode, inductor, input and output capacitors can affect switching regulator system performance.

When the LM1575/LM2575 is used as shown in the test circuit Figure 25 and Figure 26, system performance will be as shown in system

parameters of Electrical Characteristics.

ELECTRICAL CHARACTERISTICS LM1575-ADJ, LM2575-ADJ, LM2575HV-ADJ

Specifications with standard type face are for TJ= 25°C, and those with boldface type apply over full Operating

Temperature Range.LM2575-ADJ

LM1575-ADJ Units

LM2575HV-ADJ

Symbol Parameter Conditions Typ (Limits)

Limit (1) Limit (2)

SYSTEM PARAMETERS Test Circuit Figure 25 and Figure 26(3)

VOUT Feedback Voltage VIN = 12V, ILOAD = 0.2A 1.230 V

VOUT = 5V 1.217 1.217 V(Min)

Circuit Figure 25 and Figure 26 1.243 1.243 V(Max)

VOUT Feedback Voltage 0.2A ≤ILOAD ≤1A, 1.230 V

LM1575/LM2575 8V ≤VIN ≤40V 1.205/1.193 1.193/1.180 V(Min)

VOUT = 5V, Circuit Figure 25 and

Figure 26 1.255/1.267 1.267/1.280 V(Max)

VOUT Feedback Voltage 0.2A ≤ILOAD ≤1A, 1.230 V

LM2575HV 8V ≤VIN ≤60V 1.205/1.193 1.193/1.180 V(Min)

VOUT = 5V, Circuit Figure 25 and

Figure 26 1.261/1.273 1.273/1.286 V(Max)

ηEfficiency VIN = 12V, ILOAD = 1A, VOUT = 5V 77 %

(1) All limits specified at room temperature (standard type face) and at temperature extremes (bold type face). All limits are used to

calculate Average Outgoing Quality Level, and all are 100% production tested.

(2) All limits specified at room temperature (standard type face) and at temperature extremes (bold type face). All room temperature limits

are 100% production tested. All limits at temperature extremes are specified via correlation using standard Statistical Quality Control

(SQC) methods.

(3) External components such as the catch diode, inductor, input and output capacitors can affect switching regulator system performance.

When the LM1575/LM2575 is used as shown in the test circuit Figure 25 and Figure 26, system performance will be as shown in system

parameters of Electrical Characteristics.

Product Folder Links: LM1575 LM2575-N LM2575HV

LM1575, LM2575-N, LM2575HV

www.ti.com

SNVS106E –MAY 1999–REVISED APRIL 2013

ELECTRICAL CHARACTERISTICS ALL OUTPUT VOLTAGE VERSIONS

Specifications with standard type face are for TJ= 25°C, and those with boldface type apply over full Operating

Temperature Range. Unless otherwise specified, VIN = 12V for the 3.3V, 5V, and Adjustable version, VIN = 25V for the 12V

version, and VIN = 30V for the 15V version. ILOAD = 200 mA. LM2575-XX

LM1575-XX Units

LM2575HV-XX

Symbol Parameter Conditions Typ (Limits)

Limit (1) Limit (2)

DEVICE PARAMETERS

IbFeedback Bias Current VOUT = 5V (Adjustable Version Only) 50 100/500 100/500 nA

fOOscillator Frequency See (3) 52 kHz

47/43 47/42 kHz(Min)

58/62 58/63 kHz(Max)

VSAT Saturation Voltage IOUT = 1A (4) 0.9 V

1.2/1.4 1.2/1.4 V(Max)

DC Max Duty Cycle (ON) See (5) 98 %

93 93 %(Min)

ICL Current Limit Peak Current (4)(3) 2.2 A

1.7/1.3 1.7/1.3 A(Min)

3.0/3.2 3.0/3.2 A(Max)

ILOutput Leakage Output = 0V 2 2 mA(Max)

Current Output = −1V 7.5 mA

Output = −1V (6)(7) 30 30 mA(Max)

IQQuiescent Current See (6) 5 mA

10/12 10 mA(Max)

ISTBY Standby Quiescent ON /OFF Pin = 5V (OFF) 50 μA

Current 200/500 200 μA(Max)

θJA Thermal Resistance TO-220 Package, Junction to Ambient (8) 65

θJA TO-220 Package, Junction to Ambient (9) 45

θJC TO-220 Package, Junction to Case 2

θJA CDIP Package, Junction to Ambient (10) 85 °C/W

θJA SOIC Package, Junction to Ambient (10) 100

θJA DDPAK/TO-263 Package, Junction to Ambient 37

(11)

(1) All limits specified at room temperature (standard type face) and at temperature extremes (bold type face). All limits are used to

calculate Average Outgoing Quality Level, and all are 100% production tested.

(2) All limits specified at room temperature (standard type face) and at temperature extremes (bold type face). All room temperature limits

are 100% production tested. All limits at temperature extremes are specified via correlation using standard Statistical Quality Control

(SQC) methods.

(3) The oscillator frequency reduces to approximately 18 kHz in the event of an output short or an overload which causes the regulated

output voltage to drop approximately 40% from the nominal output voltage. This self protection feature lowers the average power

dissipation of the IC by lowering the minimum duty cycle from 5% down to approximately 2%.

(4) Output (pin 2) sourcing current. No diode, inductor or capacitor connected to output pin.

(5) Feedback (pin 4) removed from output and connected to 0V.

(6) Feedback (pin 4) removed from output and connected to +12V for the Adjustable, 3.3V, and 5V versions, and +25V for the 12V and 15V

versions, to force the output transistor OFF.

(7) VIN = 40V (60V for the high voltage version).

(8) Junction to ambient thermal resistance (no external heat sink) for the 5 lead TO-220 package mounted vertically, with ½ inch leads in a

socket, or on a PC board with minimum copper area.

(9) Junction to ambient thermal resistance (no external heat sink) for the 5 lead TO-220 package mounted vertically, with ½ inch leads

soldered to a PC board containing approximately 4 square inches of copper area surrounding the leads.

(10) Junction to ambient thermal resistance with approximately 1 square inch of pc board copper surrounding the leads. Additional copper

area will lower thermal resistance further. See thermal model in Switchers made Simple software.

(11) If the DDPAK/TO-263 package is used, the thermal resistance can be reduced by increasing the PC board copper area thermally

connected to the package: Using 0.5 square inches of copper area, θJA is 50°C/W; with 1 square inch of copper area, θJA is 37°C/W;

and with 1.6 or more square inches of copper area, θJA is 32°C/W.

Product Folder Links: LM1575 LM2575-N LM2575HV

LM1575, LM2575-N, LM2575HV

SNVS106E –MAY 1999–REVISED APRIL 2013

www.ti.com

ELECTRICAL CHARACTERISTICS ALL OUTPUT VOLTAGE VERSIONS (continued)

Specifications with standard type face are for TJ= 25°C, and those with boldface type apply over full Operating

Temperature Range. Unless otherwise specified, VIN = 12V for the 3.3V, 5V, and Adjustable version, VIN = 25V for the 12V

version, and VIN = 30V for the 15V version. ILOAD = 200 mA. LM2575-XX

LM1575-XX Units

LM2575HV-XX

Symbol Parameter Conditions Typ (Limits)

Limit (1) Limit (2)

ON /OFF CONTROL Test Circuit Figure 25 and Figure 26

VIH ON /OFF Pin Logic VOUT = 0V 1.4 2.2/2.4 2.2/2.4 V(Min)

Input Level

VIL VOUT = Nominal Output Voltage 1.2 1.0/0.8 1.0/0.8 V(Max)

IIH ON /OFF Pin Input ON /OFF Pin = 5V (OFF) 12 μA

Current 30 30 μA(Max)

IIL ON /OFF Pin = 0V (ON) 0 μA

10 10 μA(Max)

Product Folder Links: LM1575 LM2575-N LM2575HV

LM1575, LM2575-N, LM2575HV

www.ti.com

SNVS106E –MAY 1999–REVISED APRIL 2013

TYPICAL PERFORMANCE CHARACTERISTICS

(Circuit Figure 25 and Figure 26)

Normalized Output Voltage Line Regulation

Figure 9. Figure 10.

Dropout Voltage Current Limit

Figure 11. Figure 12.

Standby

Quiescent Current Quiescent Current

Figure 13. Figure 14.

Product Folder Links: LM1575 LM2575-N LM2575HV

LM1575, LM2575-N, LM2575HV

SNVS106E –MAY 1999–REVISED APRIL 2013

www.ti.com

TYPICAL PERFORMANCE CHARACTERISTICS (continued)

(Circuit Figure 25 and Figure 26)Switch Saturation

Oscillator Frequency Voltage

Figure 15. Figure 16.

Efficiency Minimum Operating Voltage

Figure 17. Figure 18.

Quiescent Current Feedback Voltage

vs Duty Cycle vs Duty Cycle

Figure 19. Figure 20.

Product Folder Links: LM1575 LM2575-N LM2575HV

LM1575, LM2575-N, LM2575HV

www.ti.com

SNVS106E –MAY 1999–REVISED APRIL 2013

TYPICAL PERFORMANCE CHARACTERISTICS (continued)

(Circuit Figure 25 and Figure 26)Maximum Power Dissipation

Feedback Pin Current (TO-263) (See (1))

Figure 21. Figure 22.

Switching Waveforms Load Transient Response

VOUT = 5V

A: Output Pin Voltage, 10V/div

B: Output Pin Current, 1A/div

C: Inductor Current, 0.5A/div

D: Output Ripple Voltage, 20 mV/div,

AC-Coupled

Horizontal Time Base: 5 μs/divFigure 23. Figure 24.

(1) If the DDPAK/TO-263 package is used, the thermal resistance can be reduced by increasing the PC board copper area thermally

connected to the package: Using 0.5 square inches of copper area, θJA is 50°C/W; with 1 square inch of copper area, θJA is 37°C/W;

and with 1.6 or more square inches of copper area, θJA is 32°C/W.

Product Folder Links: LM1575 LM2575-N LM2575HV

LM1575, LM2575-N, LM2575HV

SNVS106E –MAY 1999–REVISED APRIL 2013

www.ti.com

TEST CIRCUIT AND LAYOUT GUIDELINES

As in any switching regulator, layout is very important. Rapidly switching currents associated with wiring

inductance generate voltage transients which can cause problems. For minimal inductance and ground loops, the

length of the leads indicated by heavy lines should be kept as short as possible. Single-point grounding (as

indicated) or ground plane construction should be used for best results. When using the Adjustable version,

physically locate the programming resistors near the regulator, to keep the sensitive feedback wiring short.

CIN — 100 μF, 75V, Aluminum Electrolytic

COUT — 330 μF, 25V, Aluminum Electrolytic

D1 — Schottky, 11DQ06

L1 — 330 μH, PE-52627 (for 5V in, 3.3V out, use 100 μH, PE-92108)

Figure 25. Fixed Output Voltage Versions

where

VREF = 1.23V, R1 between 1k and 5k.

R1 — 2k, 0.1%

R2 — 6.12k, 0.1%

Pin numbers are for the TO-220 package.

Figure 26. Adjustable Output Voltage Version

Product Folder Links: LM1575 LM2575-N LM2575HV

LM1575, LM2575-N, LM2575HV

www.ti.com

SNVS106E –MAY 1999–REVISED APRIL 2013

LM2575 Series Buck Regulator Design Procedure

PROCEDURE (Fixed Output Voltage Versions) EXAMPLE (Fixed Output Voltage Versions)

Given: Given:

VIN(Max) = Maximum Input Voltage VOUT = 5V

VIN(Max) = 20V

VOUT = Regulated Output Voltage (3.3V, 5V, 12V, or 15V) ILOAD(Max) = 0.8A

ILOAD(Max) = Maximum Load Current

1. Inductor Selection (L1) 1. Inductor Selection (L1)

A. Select the correct Inductor value selection guide from Figure 27,A. Use the selection guide shown in Figure 28.

Figure 28,Figure 29 and Figure 30 (Output voltages of 3.3V, 5V, B. From the selection guide, the inductance area intersected by the

12V or 15V respectively). For other output voltages, see the design 20V line and 0.8A line is L330.

procedure of Figure 26 .C. Inductor value required is 330 μH. From the table in Table 2,

B. From the inductor value selection guide, identify the inductance choose AIE 415-0926, Pulse Engineering PE-52627, or RL1952.

region intersected by VIN(Max) and ILOAD(Max), and note the

inductor code for that region.

C. Identify the inductor value from the inductor code, and select an

appropriate inductor from the table shown in Table 2. Part numbers

are listed for three inductor manufacturers. The inductor chosen

must be rated for operation at the LM2575 switching frequency (52

kHz) and for a current rating of 1.15 × ILOAD. For additional inductor

information, see INDUCTOR SELECTION.

2. Output Capacitor Selection (COUT) 2. Output Capacitor Selection (COUT)

A. The value of the output capacitor together with the inductor A. COUT = 100 μF to 470 μF standard aluminum electrolytic.

defines the dominate pole-pair of the switching regulator loop. For B. Capacitor voltage rating = 20V.

stable operation and an acceptable output ripple voltage,

(approximately 1% of the output voltage) a value between 100 μF

and 470 μF is recommended.

B. The capacitor's voltage rating should be at least 1.5 times greater

than the output voltage. For a 5V regulator, a rating of at least 8V is

appropriate, and a 10V or 15V rating is recommended.

Higher voltage electrolytic capacitors generally have lower ESR

numbers, and for this reason it may be necessary to select a

capacitor rated for a higher voltage than would normally be needed.

3. Catch Diode Selection (D1) 3. Catch Diode Selection (D1)

A. The catch-diode current rating must be at least 1.2 times greater A. For this example, a 1A current rating is adequate.

than the maximum load current. Also, if the power supply design B. Use a 30V 1N5818 or SR103 Schottky diode, or any of the

must withstand a continuous output short, the diode should have a suggested fast-recovery diodes shown in Table 1.

current rating equal to the maximum current limit of the LM2575. The

most stressful condition for this diode is an overload or shorted

output condition.

B. The reverse voltage rating of the diode should be at least 1.25

times the maximum input voltage.

4. Input Capacitor (CIN) 4. Input Capacitor (CIN)

An aluminum or tantalum electrolytic bypass capacitor located close A 47 μF, 25V aluminum electrolytic capacitor located near the input

to the regulator is needed for stable operation. and ground pins provides sufficient bypassing.

Product Folder Links: LM1575 LM2575-N LM2575HV

LM1575, LM2575-N, LM2575HV

SNVS106E –MAY 1999–REVISED APRIL 2013

www.ti.com

Inductor Value Selection Guides

(For Continuous Mode Operation)

Figure 27. LM2575(HV)-3.3 Figure 28. LM2575(HV)-5.0

Figure 29. LM2575(HV)-12 Figure 30. LM2575(HV)-15

Figure 31. LM2575(HV)-ADJ

Product Folder Links: LM1575 LM2575-N LM2575HV

LM1575, LM2575-N, LM2575HV

www.ti.com

SNVS106E –MAY 1999–REVISED APRIL 2013

PROCEDURE (Adjustable Output Voltage Versions) EXAMPLE (Adjustable Output Voltage Versions)

Given: Given:

VOUT = Regulated Output Voltage VOUT = 10V

VIN(Max) = Maximum Input Voltage VIN(Max) = 25V

ILOAD(Max) = Maximum Load Current ILOAD(Max) = 1A

F = Switching Frequency (Fixed at 52 kHz) F = 52 kHz

1. Programming Output Voltage (Selecting R1 and R2, as shown 1. Programming Output Voltage (Selecting R1 and R2)

in Figure 25 and Figure 26)

Use the following formula to select the appropriate resistor values.

(1) (3)

R1can be between 1k and 5k. (For best temperature coefficient and R2 = 1k (8.13 −1) = 7.13k, closest 1% value is 7.15k

stability with time, use 1% metal film resistors)

(2)

2. Inductor Selection (L1) 2. Inductor Selection (L1)

A. Calculate the inductor Volt • microsecond constant, A. Calculate E • T (V • μs)

E • T (V • μs), from the following formula:

(5)

(4) B. E • T = 115 V • μs

B. Use the E • T value from the previous formula and match it with C. ILOAD(Max) = 1A

the E • T number on the vertical axis of the Inductor Value D. Inductance Region = H470

Selection Guide shown in Figure 31.E. Inductor Value = 470 μHChoose from AIE part #430-0634, Pulse

C. On the horizontal axis, select the maximum load current. Engineering part #PE-53118, or Renco part #RL-1961.

D. Identify the inductance region intersected by the E • T value and

the maximum load current value, and note the inductor code for that

region.

E. Identify the inductor value from the inductor code, and select an

appropriate inductor from the table shown in Table 2. Part numbers

are listed for three inductor manufacturers. The inductor chosen

must be rated for operation at the LM2575 switching frequency (52

kHz) and for a current rating of 1.15 × ILOAD. For additional inductor

information, see INDUCTOR SELECTION.

3. Output Capacitor Selection (COUT) 3. Output Capacitor Selection (COUT)

A. The value of the output capacitor together with the inductor A.

defines the dominate pole-pair of the switching regulator loop. For

stable operation, the capacitor must satisfy the following (7)

requirement: However, for acceptable output ripple voltage select

COUT ≥220 μF

(6) COUT = 220 μF electrolytic capacitor

The above formula yields capacitor values between 10 μF and 2000

μF that will satisfy the loop requirements for stable operation. But to

achieve an acceptable output ripple voltage, (approximately 1% of

the output voltage) and transient response, the output capacitor may

need to be several times larger than the above formula yields.

B. The capacitor's voltage rating should be at last 1.5 times greater

than the output voltage. For a 10V regulator, a rating of at least 15V

or more is recommended.

Higher voltage electrolytic capacitors generally have lower ESR

numbers, and for this reason it may be necessary to select a

capacitor rate for a higher voltage than would normally be needed.

(Continued) (Continued)

Product Folder Links: LM1575 LM2575-N LM2575HV

LM1575, LM2575-N, LM2575HV

SNVS106E –MAY 1999–REVISED APRIL 2013

www.ti.com

PROCEDURE (Adjustable Output Voltage Versions) EXAMPLE (Adjustable Output Voltage Versions)

4. Catch Diode Selection (D1) 4. Catch Diode Selection (D1)

A. The catch-diode current rating must be at least 1.2 times greater A. For this example, a 3A current rating is adequate.

than the maximum load current. Also, if the power supply design B. Use a 40V MBR340 or 31DQ04 Schottky diode, or any of the

must withstand a continuous output short, the diode should have a suggested fast-recovery diodes in Table 1.

current rating equal to the maximum current limit of the LM2575. The

most stressful condition for this diode is an overload or shorted

output. See Table 1.

B. The reverse voltage rating of the diode should be at least 1.25

times the maximum input voltage.

5. Input Capacitor (CIN) 5. Input Capacitor (CIN)

An aluminum or tantalum electrolytic bypass capacitor located close A 100 μF aluminum electrolytic capacitor located near the input and

to the regulator is needed for stable operation. ground pins provides sufficient bypassing.

To further simplify the buck regulator design procedure, TI is making available computer design software to be

used with the Simple Switcher line of switching regulators. Switchers Made Simple (version 3.3) is available on

a (3½″) diskette for IBM compatible computers from a TI sales office in your area.

Table 1. Diode Selection Guide

Schottky Fast Recovery

VR1A 3A 1A 3A

20V 1N5817 1N5820

MBR120P MBR320 The following The following

SR102 SR302 diodes are all diodes are all

30V 1N5818 1N5821

MBR130P MBR330 rated to 100V: rated to 100V:

11DQ03 31DQ03 11DF1 31DF1

SR103 SR303 MUR110 MURD310

HER102 HER302

40V 1N5819 IN5822

MBR140P MBR340

11DQ04 31DQ04

SR104 SR304

50V MBR150 MBR350

11DQ05 31DQ05

SR105 SR305

60V MBR160 MBR360

11DQ06 31DQ06

SR106 SR306

Table 2. Inductor Selection by Manufacturer's Part Number

Inductor Code Inductor Value Schott (1) Pulse Eng. (2) Renco (3)

L100 100 μH 67127000 PE-92108 RL2444

L150 150 μH 67127010 PE-53113 RL1954

L220 220 μH 67127020 PE-52626 RL1953

L330 330 μH 67127030 PE-52627 RL1952

L470 470 μH 67127040 PE-53114 RL1951

L680 680 μH 67127050 PE-52629 RL1950

H150 150 μH 67127060 PE-53115 RL2445

H220 220 μH 67127070 PE-53116 RL2446

H330 330 μH 67127080 PE-53117 RL2447

H470 470 μH 67127090 PE-53118 RL1961

H680 680 μH 67127100 PE-53119 RL1960

H1000 1000 μH 67127110 PE-53120 RL1959

(1) Schott Corp., (612) 475-1173, 1000 Parkers Lake Rd., Wayzata, MN 55391.

(2) Pulse Engineering, (619) 674-8100, P.O. Box 12236, San Diego, CA 92112.

(3) Renco Electronics Inc., (516) 586-5566, 60 Jeffryn Blvd. East, Deer Park, NY 11729.

Product Folder Links: LM1575 LM2575-N LM2575HV

LM1575, LM2575-N, LM2575HV

www.ti.com

SNVS106E –MAY 1999–REVISED APRIL 2013

Table 2. Inductor Selection by Manufacturer's Part Number (continued)

Inductor Code Inductor Value Schott (1) Pulse Eng. (2) Renco (3)

H1500 1500 μH 67127120 PE-53121 RL1958

H2200 2200 μH 67127130 PE-53122 RL2448

APPLICATION HINTS

INPUT CAPACITOR (CIN)

To maintain stability, the regulator input pin must be bypassed with at least a 47 μF electrolytic capacitor. The

capacitor's leads must be kept short, and located near the regulator.

If the operating temperature range includes temperatures below −25°C, the input capacitor value may need to be

larger. With most electrolytic capacitors, the capacitance value decreases and the ESR increases with lower

temperatures and age. Paralleling a ceramic or solid tantalum capacitor will increase the regulator stability at cold

temperatures. For maximum capacitor operating lifetime, the capacitor's RMS ripple current rating should be

greater than

(8)

INDUCTOR SELECTION

All switching regulators have two basic modes of operation: continuous and discontinuous. The difference

between the two types relates to the inductor current, whether it is flowing continuously, or if it drops to zero for a

period of time in the normal switching cycle. Each mode has distinctively different operating characteristics,

which can affect the regulator performance and requirements.

The LM2575 (or any of the Simple Switcher family) can be used for both continuous and discontinuous modes of

operation.

The inductor value selection guides in Figure 27 through Figure 31 were designed for buck regulator designs of

the continuous inductor current type. When using inductor values shown in the inductor selection guide, the

peak-to-peak inductor ripple current will be approximately 20% to 30% of the maximum DC current. With

relatively heavy load currents, the circuit operates in the continuous mode (inductor current always flowing), but

under light load conditions, the circuit will be forced to the discontinuous mode (inductor current falls to zero for a

period of time). This discontinuous mode of operation is perfectly acceptable. For light loads (less than

approximately 200 mA) it may be desirable to operate the regulator in the discontinuous mode, primarily because

of the lower inductor values required for the discontinuous mode.

The selection guide chooses inductor values suitable for continuous mode operation, but if the inductor value

chosen is prohibitively high, the designer should investigate the possibility of discontinuous operation. The

computer design software Switchers Made Simple will provide all component values for discontinuous (as well

as continuous) mode of operation.

Inductors are available in different styles such as pot core, toriod, E-frame, bobbin core, etc., as well as different

core materials, such as ferrites and powdered iron. The least expensive, the bobbin core type, consists of wire

wrapped on a ferrite rod core. This type of construction makes for an inexpensive inductor, but since the

magnetic flux is not completely contained within the core, it generates more electromagnetic interference (EMI).

This EMI can cause problems in sensitive circuits, or can give incorrect scope readings because of induced

voltages in the scope probe.

The inductors listed in the selection chart include ferrite pot core construction for AIE, powdered iron toroid for

Pulse Engineering, and ferrite bobbin core for Renco.

Product Folder Links: LM1575 LM2575-N LM2575HV

LM1575, LM2575-N, LM2575HV

SNVS106E –MAY 1999–REVISED APRIL 2013

www.ti.com

An inductor should not be operated beyond its maximum rated current because it may saturate. When an

inductor begins to saturate, the inductance decreases rapidly and the inductor begins to look mainly resistive (the

DC resistance of the winding). This will cause the switch current to rise very rapidly. Different inductor types have

different saturation characteristics, and this should be kept in mind when selecting an inductor.

The inductor manufacturer's data sheets include current and energy limits to avoid inductor saturation.

INDUCTOR RIPPLE CURRENT

When the switcher is operating in the continuous mode, the inductor current waveform ranges from a triangular

to a sawtooth type of waveform (depending on the input voltage). For a given input voltage and output voltage,

the peak-to-peak amplitude of this inductor current waveform remains constant. As the load current rises or falls,

the entire sawtooth current waveform also rises or falls. The average DC value of this waveform is equal to the

DC load current (in the buck regulator configuration).

If the load current drops to a low enough level, the bottom of the sawtooth current waveform will reach zero, and

the switcher will change to a discontinuous mode of operation. This is a perfectly acceptable mode of operation.

Any buck switching regulator (no matter how large the inductor value is) will be forced to run discontinuous if the

load current is light enough.

OUTPUT CAPACITOR

An output capacitor is required to filter the output voltage and is needed for loop stability. The capacitor should

be located near the LM2575 using short pc board traces. Standard aluminum electrolytics are usually adequate,

but low ESR types are recommended for low output ripple voltage and good stability. The ESR of a capacitor

depends on many factors, some which are: the value, the voltage rating, physical size and the type of

construction. In general, low value or low voltage (less than 12V) electrolytic capacitors usually have higher ESR

numbers.

The amount of output ripple voltage is primarily a function of the ESR (Equivalent Series Resistance) of the

output capacitor and the amplitude of the inductor ripple current (ΔIIND). (See INDUCTOR RIPPLE CURRENT).

The lower capacitor values (220 μF–680 μF) will allow typically 50 mV to 150 mV of output ripple voltage, while

larger-value capacitors will reduce the ripple to approximately 20 mV to 50 mV.

Output Ripple Voltage = (ΔIIND) (ESR of COUT) (9)

To further reduce the output ripple voltage, several standard electrolytic capacitors may be paralleled, or a

higher-grade capacitor may be used. Such capacitors are often called “high-frequency,” “low-inductance,” or

“low-ESR.” These will reduce the output ripple to 10 mV or 20 mV. However, when operating in the continuous

mode, reducing the ESR below 0.05Ωcan cause instability in the regulator.

Tantalum capacitors can have a very low ESR, and should be carefully evaluated if it is the only output capacitor.

Because of their good low temperature characteristics, a tantalum can be used in parallel with aluminum

electrolytics, with the tantalum making up 10% or 20% of the total capacitance.

The capacitor's ripple current rating at 52 kHz should be at least 50% higher than the peak-to-peak inductor

ripple current.

CATCH DIODE

Buck regulators require a diode to provide a return path for the inductor current when the switch is off. This diode

should be located close to the LM2575 using short leads and short printed circuit traces.

Because of their fast switching speed and low forward voltage drop, Schottky diodes provide the best efficiency,

especially in low output voltage switching regulators (less than 5V). Fast-Recovery, High-Efficiency, or Ultra-Fast

Recovery diodes are also suitable, but some types with an abrupt turn-off characteristic may cause instability and

EMI problems. A fast-recovery diode with soft recovery characteristics is a better choice. Standard 60 Hz diodes

(example: 1N4001 or 1N5400, and so on.) are also not suitable. See Table 1 for Schottky and “soft” fast-

recovery diode selection guide.

Product Folder Links: LM1575 LM2575-N LM2575HV

LM1575, LM2575-N, LM2575HV

www.ti.com

SNVS106E –MAY 1999–REVISED APRIL 2013

OUTPUT VOLTAGE RIPPLE AND TRANSIENTS

The output voltage of a switching power supply will contain a sawtooth ripple voltage at the switcher frequency,

typically about 1% of the output voltage, and may also contain short voltage spikes at the peaks of the sawtooth

waveform.

The output ripple voltage is due mainly to the inductor sawtooth ripple current multiplied by the ESR of the output

capacitor. (See INDUCTOR SELECTION)

The voltage spikes are present because of the fast switching action of the output switch, and the parasitic

inductance of the output filter capacitor. To minimize these voltage spikes, special low inductance capacitors can

be used, and their lead lengths must be kept short. Wiring inductance, stray capacitance, as well as the scope

probe used to evaluate these transients, all contribute to the amplitude of these spikes.

An additional small LC filter (20 μH & 100 μF) can be added to the output (as shown in Figure 37) to further

reduce the amount of output ripple and transients. A 10 × reduction in output ripple voltage and transients is

possible with this filter.

FEEDBACK CONNECTION

The LM2575 (fixed voltage versions) feedback pin must be wired to the output voltage point of the switching

power supply. When using the adjustable version, physically locate both output voltage programming resistors

near the LM2575 to avoid picking up unwanted noise. Avoid using resistors greater than 100 kΩbecause of the

increased chance of noise pickup.

ON /OFF INPUT

For normal operation, the ON /OFF pin should be grounded or driven with a low-level TTL voltage (typically

below 1.6V). To put the regulator into standby mode, drive this pin with a high-level TTL or CMOS signal. The

ON /OFF pin can be safely pulled up to +VIN without a resistor in series with it. The ON /OFF pin should not be

left open.

GROUNDING

To maintain output voltage stability, the power ground connections must be low-impedance (see Figure 26). For

the TO-3 style package, the case is ground. For the 5-lead TO-220 style package, both the tab and pin 3 are

ground and either connection may be used, as they are both part of the same copper lead frame.

With the CDIP or SOIC packages, all the pins labeled ground, power ground, or signal ground should be

soldered directly to wide printed circuit board copper traces. This assures both low inductance connections and

good thermal properties.

HEAT SINK/THERMAL CONSIDERATIONS

In many cases, no heat sink is required to keep the LM2575 junction temperature within the allowed operating

range. For each application, to determine whether or not a heat sink will be required, the following must be

identified:

1. Maximum ambient temperature (in the application).

2. Maximum regulator power dissipation (in application).

3. Maximum allowed junction temperature (150°C for the LM1575 or 125°C for the LM2575). For a safe,

conservative design, a temperature approximately 15°C cooler than the maximum temperature should be

selected.

4. LM2575 package thermal resistances θJA and θJC.

Total power dissipated by the LM2575 can be estimated as follows:

PD= (VIN) (IQ) + (VO/VIN) (ILOAD) (VSAT)

where

• IQ(quiescent current) and VSAT can be found in the Characteristic Curves shown previously,

• VIN is the applied minimum input voltage,

• VOis the regulated output voltage

• and ILOAD is the load current. (10)

Product Folder Links: LM1575 LM2575-N LM2575HV

LM1575, LM2575-N, LM2575HV

SNVS106E –MAY 1999–REVISED APRIL 2013

www.ti.com

The dynamic losses during turn-on and turn-off are negligible if a Schottky type catch diode is used.

When no heat sink is used, the junction temperature rise can be determined by the following:

ΔTJ= (PD) (θJA) (11)

To arrive at the actual operating junction temperature, add the junction temperature rise to the maximum ambient

temperature.

TJ=ΔTJ+ TA(12)

If the actual operating junction temperature is greater than the selected safe operating junction temperature

determined in step 3, then a heat sink is required.

When using a heat sink, the junction temperature rise can be determined by the following:

ΔTJ= (PD) (θJC +θinterface +θHeat sink) (13)

The operating junction temperature will be:

TJ= TA+ΔTJ(14)

As shown in Equation 14, if the actual operating junction temperature is greater than the selected safe operating

junction temperature, then a larger heat sink is required (one that has a lower thermal resistance).

When using the LM2575 in the plastic CDIP or surface mount SOIC packages, several items about the thermal

properties of the packages should be understood. The majority of the heat is conducted out of the package

through the leads, with a minor portion through the plastic parts of the package. Since the lead frame is solid

copper, heat from the die is readily conducted through the leads to the printed circuit board copper, which is

acting as a heat sink.

For best thermal performance, the ground pins and all the unconnected pins should be soldered to generous

amounts of printed circuit board copper, such as a ground plane. Large areas of copper provide the best transfer

of heat to the surrounding air. Copper on both sides of the board is also helpful in getting the heat away from the

package, even if there is no direct copper contact between the two sides. Thermal resistance numbers as low as

40°C/W for the SOIC package, and 30°C/W for the CDIP package can be realized with a carefully engineered pc

board.

Included on the Switchers Made Simple design software is a more precise (non-linear) thermal model that can

be used to determine junction temperature with different input-output parameters or different component values.

It can also calculate the heat sink thermal resistance required to maintain the regulators junction temperature

below the maximum operating temperature.

ADDITIONAL APPLICATIONS

INVERTING REGULATOR

Figure 32 shows a LM2575-12 in a buck-boost configuration to generate a negative 12V output from a positive

input voltage. This circuit bootstraps the regulator's ground pin to the negative output voltage, then by grounding

the feedback pin, the regulator senses the inverted output voltage and regulates it to −12V.

For an input voltage of 12V or more, the maximum available output current in this configuration is approximately

0.35A. At lighter loads, the minimum input voltage required drops to approximately 4.7V.

The switch currents in this buck-boost configuration are higher than in the standard buck-mode design, thus

lowering the available output current. Also, the start-up input current of the buck-boost converter is higher than

the standard buck-mode regulator, and this may overload an input power source with a current limit less than

1.5A. Using a delayed turn-on or an undervoltage lockout circuit (described in the NEGATIVE BOOST

REGULATOR section) would allow the input voltage to rise to a high enough level before the switcher would be

allowed to turn on.

Because of the structural differences between the buck and the buck-boost regulator topologies, the buck

regulator design procedure section cannot be used to select the inductor or the output capacitor. The

recommended range of inductor values for the buck-boost design is between 68 μH and 220 μH, and the output

capacitor values must be larger than what is normally required for buck designs. Low input voltages or high

output currents require a large value output capacitor (in the thousands of micro Farads).

Product Folder Links: LM1575 LM2575-N LM2575HV

LM1575, LM2575-N, LM2575HV

www.ti.com

SNVS106E –MAY 1999–REVISED APRIL 2013

The peak inductor current, which is the same as the peak switch current, can be calculated from the following

formula:

where

• fosc = 52 kHz. (15)

Under normal continuous inductor current operating conditions, the minimum VIN represents the worst case.

Select an inductor that is rated for the peak current anticipated.

Also, the maximum voltage appearing across the regulator is the absolute sum of the input and output voltage.

For a −12V output, the maximum input voltage for the LM2575 is +28V, or +48V for the LM2575HV.

The Switchers Made Simple (version 3.3) design software can be used to determine the feasibility of regulator

designs using different topologies, different input-output parameters, different components, and so on.

Figure 32. Inverting Buck-Boost Develops −12V

NEGATIVE BOOST REGULATOR

Another variation on the buck-boost topology is the negative boost configuration. The circuit in Figure 33 accepts

an input voltage ranging from −5V to −12V and provides a regulated −12V output. Input voltages greater than

−12V will cause the output to rise above −12V, but will not damage the regulator.

Because of the boosting function of this type of regulator, the switch current is relatively high, especially at low

input voltages. Output load current limitations are a result of the maximum current rating of the switch. Also,

boost regulators can not provide current limiting load protection in the event of a shorted load, so some other

means (such as a fuse) may be necessary.

Product Folder Links: LM1575 LM2575-N LM2575HV

LM2575-12

3 5

+1N5817

+COUT

1000 PF

Feedback

Output

VIN

CIN

100 PFGND

150 PH

VOUT = -12V

-VIN

-5V to -12V

Low ESR

ON/OFF

LM1575, LM2575-N, LM2575HV

SNVS106E –MAY 1999–REVISED APRIL 2013

www.ti.com

Typical Load Current

200 mA for VIN =−5.2V

500 mA for VIN =−7V

Pin numbers are for TO-220 package.

Figure 33. Negative Boost

UNDERVOLTAGE LOCKOUT

In some applications it is desirable to keep the regulator off until the input voltage reaches a certain threshold. An

undervoltage lockout circuit which accomplishes this task is shown in Figure 34, while Figure 35 shows the same

circuit applied to a buck-boost configuration. These circuits keep the regulator off until the input voltage reaches

a predetermined level.

VTH ≈VZ1 + 2VBE (Q1) (16)

DELAYED STARTUP

The ON /OFF pin can be used to provide a delayed startup feature as shown in Figure 36. With an input voltage

of 20V and for the part values shown, the circuit provides approximately 10 ms of delay time before the circuit

begins switching. Increasing the RC time constant can provide longer delay times. But excessively large RC time

constants can cause problems with input voltages that are high in 60 Hz or 120 Hz ripple, by coupling the ripple

into the ON /OFF pin.

ADJUSTABLE OUTPUT, LOW-RIPPLE

POWER SUPPLY

A 1A power supply that features an adjustable output voltage is shown in Figure 37. An additional L-C filter that

reduces the output ripple by a factor of 10 or more is included in this circuit.

Product Folder Links: LM1575 LM2575-N LM2575HV

LM1575, LM2575-N, LM2575HV

www.ti.com

SNVS106E –MAY 1999–REVISED APRIL 2013

Complete circuit not shown.

Pin numbers are for the TO-220 package.

Figure 34. Undervoltage Lockout for Buck Circuit

Complete circuit not shown (see Figure 32).

Pin numbers are for the TO-220 package.

Figure 35. Undervoltage Lockout

for Buck-Boost Circuit

Complete circuit not shown.

Pin numbers are for the TO-220 package.

Figure 36. Delayed Startup

Product Folder Links: LM1575 LM2575-N LM2575HV

LM1575, LM2575-N, LM2575HV

SNVS106E –MAY 1999–REVISED APRIL 2013

www.ti.com

Pin numbers are for the TO-220 package.

Figure 37. 1.2V to 55V Adjustable 1A Power Supply with Low Output Ripple

Definition of Terms

BUCK REGULATORA switching regulator topology in which a higher voltage is converted to a lower voltage.

Also known as a step-down switching regulator.

BUCK-BOOST REGULATORA switching regulator topology in which a positive voltage is converted to a

negative voltage without a transformer.

DUTY CYCLE (D)Ratio of the output switch's on-time to the oscillator period.

(17)

CATCH DIODE OR CURRENT STEERING DIODEThe diode which provides a return path for the load current

when the LM2575 switch is OFF.

EFFICIENCY (η)The proportion of input power actually delivered to the load.

(18)

CAPACITOR EQUIVALENT SERIES RESISTANCE (ESR)The purely resistive component of a real capacitor's

impedance (see Figure 38). It causes power loss resulting in capacitor heating, which directly affects the

capacitor's operating lifetime. When used as a switching regulator output filter, higher ESR values result in

higher output ripple voltages.

Figure 38. Simple Model of a Real Capacitor

Most standard aluminum electrolytic capacitors in the 100 μF–1000 μF range have 0.5Ωto

0.1ΩESR. Higher-grade capacitors (“low-ESR”, “high-frequency”, or “low-inductance”') in the

100 μF–1000 μF range generally have ESR of less than 0.15Ω.

EQUIVALENT SERIES INDUCTANCE (ESL)The pure inductance component of a capacitor (see Figure 38).

The amount of inductance is determined to a large extent on the capacitor's construction. In a buck

regulator, this unwanted inductance causes voltage spikes to appear on the output.

OUTPUT RIPPLE VOLTAGEThe AC component of the switching regulator's output voltage. It is usually

dominated by the output capacitor's ESR multiplied by the inductor's ripple current (ΔIIND). The peak-to-

peak value of this sawtooth ripple current can be determined by reading INDUCTOR RIPPLE CURRENT.

Product Folder Links: LM1575 LM2575-N LM2575HV

LM1575, LM2575-N, LM2575HV

www.ti.com

SNVS106E –MAY 1999–REVISED APRIL 2013

CAPACITOR RIPPLE CURRENTRMS value of the maximum allowable alternating current at which a capacitor

can be operated continuously at a specified temperature.

STANDBY QUIESCENT CURRENT (ISTBY)Supply current required by the LM2575 when in the standby mode

(ON /OFF pin is driven to TTL-high voltage, thus turning the output switch OFF).

INDUCTOR RIPPLE CURRENT (ΔIIND)The peak-to-peak value of the inductor current waveform, typically a

sawtooth waveform when the regulator is operating in the continuous mode (vs. discontinuous mode).

CONTINUOUS/DISCONTINUOUS MODE OPERATIONRelates to the inductor current. In the continuous mode,

the inductor current is always flowing and never drops to zero, vs. the discontinuous mode, where the

inductor current drops to zero for a period of time in the normal switching cycle.

INDUCTOR SATURATIONThe condition which exists when an inductor cannot hold any more magnetic flux.

When an inductor saturates, the inductor appears less inductive and the resistive component dominates.

Inductor current is then limited only by the DC resistance of the wire and the available source current.

OPERATING VOLT MICROSECOND CONSTANT (E•Top)The product (in VoIt•μs) of the voltage applied to the

inductor and the time the voltage is applied. This E•Top constant is a measure of the energy handling

capability of an inductor and is dependent upon the type of core, the core area, the number of turns, and

the duty cycle.

Product Folder Links: LM1575 LM2575-N LM2575HV

LM1575, LM2575-N, LM2575HV

SNVS106E –MAY 1999–REVISED APRIL 2013

www.ti.com

REVISION HISTORY

Changes from Revision D (April 2013) to Revision E Page

• Changed layout of National Data Sheet to TI format .......................................................................................................... 25

Product Folder Links: LM1575 LM2575-N LM2575HV

PACKAGE OPTION ADDENDUM

www.ti.com 26-Feb-2021

Addendum-Page 1

PACKAGING INFORMATION

Orderable Device Status

(1)

Package Type Package

Drawing Pins Package

Qty Eco Plan

(2)

Lead finish/

Ball material

(6)

MSL Peak Temp

(3)

Op Temp (°C) Device Marking

(4/5)

Samples

LM2575HVS-12 NRND DDPAK/

TO-263 KTT 5 45 Non-RoHS

& Green Call TI Call TI -40 to 125 LM2575HVS

-12 P+

LM2575HVS-12/NOPB ACTIVE DDPAK/

TO-263 KTT 5 45 RoHS-Exempt

& Green SN Level-3-245C-168 HR -40 to 125 LM2575HVS

-12 P+

LM2575HVS-15 NRND DDPAK/

TO-263 KTT 5 45 Non-RoHS

& Green Call TI Call TI -40 to 125 LM2575HVS

-15 P+

LM2575HVS-15/NOPB ACTIVE DDPAK/

TO-263 KTT 5 45 RoHS-Exempt

& Green SN Level-3-245C-168 HR -40 to 125 LM2575HVS

-15 P+

LM2575HVS-3.3/NOPB ACTIVE DDPAK/

TO-263 KTT 5 45 RoHS-Exempt

& Green SN Level-3-245C-168 HR -40 to 125 LM2575HVS

-3.3 P+

LM2575HVS-5.0 NRND DDPAK/

TO-263 KTT 5 45 Non-RoHS

& Green Call TI Call TI -40 to 125 LM2575HVS

-5.0 P+

LM2575HVS-5.0/NOPB ACTIVE DDPAK/

TO-263 KTT 5 45 RoHS-Exempt

& Green SN Level-3-245C-168 HR -40 to 125 LM2575HVS

-5.0 P+

LM2575HVS-ADJ NRND DDPAK/

TO-263 KTT 5 45 Non-RoHS

& Green Call TI Call TI -40 to 125 LM2575HVS

-ADJ P+

LM2575HVS-ADJ/NOPB ACTIVE DDPAK/

TO-263 KTT 5 45 RoHS-Exempt

& Green SN Level-3-245C-168 HR -40 to 125 LM2575HVS

-ADJ P+

LM2575HVSX-15/NOPB ACTIVE DDPAK/

TO-263 KTT 5 500 RoHS-Exempt

& Green SN Level-3-245C-168 HR -40 to 125 LM2575HVS

-15 P+

LM2575HVSX-3.3/NOPB ACTIVE DDPAK/

TO-263 KTT 5 500 RoHS-Exempt

& Green SN Level-3-245C-168 HR -40 to 125 LM2575HVS

-3.3 P+

LM2575HVSX-5.0 NRND DDPAK/

TO-263 KTT 5 500 Non-RoHS

& Green Call TI Call TI -40 to 125 LM2575HVS

-5.0 P+

LM2575HVSX-5.0/NOPB ACTIVE DDPAK/

TO-263 KTT 5 500 RoHS-Exempt

& Green SN Level-3-245C-168 HR -40 to 125 LM2575HVS

-5.0 P+

LM2575HVSX-ADJ NRND DDPAK/

TO-263 KTT 5 500 Non-RoHS

& Green Call TI Call TI -40 to 125 LM2575HVS

-ADJ P+

LM2575HVSX-ADJ/NOPB ACTIVE DDPAK/

TO-263 KTT 5 500 RoHS-Exempt

& Green SN Level-3-245C-168 HR -40 to 125 LM2575HVS

-ADJ P+

LM2575HVT-12 NRND TO-220 KC 5 45 Non-RoHS

& Green Call TI Call TI -40 to 125 LM2575HVT

-12 P+

PACKAGE OPTION ADDENDUM

www.ti.com 26-Feb-2021

Addendum-Page 2

Orderable Device Status

(1)

Package Type Package

Drawing Pins Package

Qty Eco Plan

(2)

Lead finish/

Ball material

(6)

MSL Peak Temp

(3)

Op Temp (°C) Device Marking

(4/5)

Samples

LM2575HVT-12/LB03 NRND TO-220 NDH 5 45 Non-RoHS

& Green Call TI Call TI LM2575HVT

-12 P+

LM2575HVT-12/LF03 ACTIVE TO-220 NDH 5 45 RoHS & Green SN Level-1-NA-UNLIM LM2575HVT

-12 P+

LM2575HVT-12/NOPB ACTIVE TO-220 KC 5 45 RoHS & Green SN Level-1-NA-UNLIM -40 to 125 LM2575HVT

-12 P+

LM2575HVT-15 NRND TO-220 KC 5 45 Non-RoHS

& Green Call TI Call TI -40 to 125 LM2575HVT

-15 P+

LM2575HVT-15/LB03 NRND TO-220 NDH 5 45 Non-RoHS

& Green Call TI Call TI LM2575HVT

-15 P+

LM2575HVT-15/LF03 ACTIVE TO-220 NDH 5 45 RoHS & Green SN Level-1-NA-UNLIM LM2575HVT

-15 P+

LM2575HVT-15/NOPB ACTIVE TO-220 KC 5 45 RoHS & Green SN Level-1-NA-UNLIM -40 to 125 LM2575HVT

-15 P+

LM2575HVT-3.3/LF03 ACTIVE TO-220 NDH 5 45 RoHS & Green SN Level-1-NA-UNLIM LM2575HVT

-3.3 P+

LM2575HVT-3.3/NOPB ACTIVE TO-220 KC 5 45 RoHS & Green SN Level-1-NA-UNLIM -40 to 125 LM2575HVT

-3.3 P+

LM2575HVT-5.0 NRND TO-220 KC 5 45 Non-RoHS

& Green Call TI Call TI -40 to 125 LM2575HVT

-5.0 P+

LM2575HVT-5.0/LB03 NRND TO-220 NDH 5 45 Non-RoHS

& Green Call TI Call TI LM2575HVT

-5.0 P+

LM2575HVT-5.0/LF03 ACTIVE TO-220 NDH 5 45 RoHS & Green SN Level-1-NA-UNLIM LM2575HVT

-5.0 P+

LM2575HVT-5.0/NOPB ACTIVE TO-220 KC 5 45 RoHS & Green SN Level-1-NA-UNLIM -40 to 125 LM2575HVT

-5.0 P+

LM2575HVT-ADJ NRND TO-220 KC 5 45 Non-RoHS

& Green Call TI Call TI -40 to 125 LM2575HVT

-ADJ P+

LM2575HVT-ADJ/LB03 NRND TO-220 NDH 5 45 Non-RoHS

& Green Call TI Call TI LM2575HVT

-ADJ P+

LM2575HVT-ADJ/LF03 ACTIVE TO-220 NDH 5 45 RoHS & Green SN Level-1-NA-UNLIM LM2575HVT

-ADJ P+

LM2575HVT-ADJ/NOPB ACTIVE TO-220 KC 5 45 RoHS & Green SN Level-1-NA-UNLIM -40 to 125 LM2575HVT

-ADJ P+

PACKAGE OPTION ADDENDUM

www.ti.com 26-Feb-2021

Addendum-Page 3

Orderable Device Status

(1)

Package Type Package

Drawing Pins Package

Qty Eco Plan

(2)

Lead finish/

Ball material

(6)

MSL Peak Temp

(3)

Op Temp (°C) Device Marking

(4/5)

Samples

LM2575M-5.0 NRND SOIC DW 24 30 Non-RoHS

& Green Call TI Call TI -40 to 125 LM2575M

-5.0 P+

LM2575M-5.0/NOPB ACTIVE SOIC DW 24 30 RoHS & Green SN Level-3-260C-168 HR -40 to 125 LM2575M

-5.0 P+

LM2575M-ADJ/NOPB ACTIVE SOIC DW 24 30 RoHS & Green SN Level-3-260C-168 HR -40 to 125 LM2575M

-ADJ P+

LM2575MX-5.0/NOPB ACTIVE SOIC DW 24 1000 RoHS & Green SN Level-3-260C-168 HR -40 to 125 LM2575M

-5.0 P+

LM2575MX-ADJ/NOPB ACTIVE SOIC DW 24 1000 RoHS & Green SN Level-3-260C-168 HR -40 to 125 LM2575M

-ADJ P+

LM2575S-12/NOPB ACTIVE DDPAK/

TO-263 KTT 5 45 RoHS-Exempt

& Green SN Level-3-245C-168 HR -40 to 125 LM2575S

-12 P+

LM2575S-15/NOPB ACTIVE DDPAK/

TO-263 KTT 5 45 RoHS-Exempt

& Green SN Level-3-245C-168 HR -40 to 125 LM2575S

-15 P+

LM2575S-3.3 NRND DDPAK/

TO-263 KTT 5 45 Non-RoHS

& Green Call TI Call TI -40 to 125 LM2575S

-3.3 P+

LM2575S-3.3/NOPB ACTIVE DDPAK/

TO-263 KTT 5 45 RoHS-Exempt

& Green SN Level-3-245C-168 HR -40 to 125 LM2575S

-3.3 P+

LM2575S-5.0 NRND DDPAK/

TO-263 KTT 5 45 Non-RoHS

& Green Call TI Call TI -40 to 125 LM2575S

-5.0 P+

LM2575S-5.0/NOPB ACTIVE DDPAK/

TO-263 KTT 5 45 RoHS-Exempt

& Green SN Level-3-245C-168 HR -40 to 125 LM2575S

-5.0 P+

LM2575S-ADJ NRND DDPAK/

TO-263 KTT 5 45 Non-RoHS

& Green Call TI Call TI -40 to 125 LM2575S

-ADJ P+

LM2575S-ADJ/NOPB ACTIVE DDPAK/

TO-263 KTT 5 45 RoHS-Exempt

& Green SN Level-3-245C-168 HR -40 to 125 LM2575S

-ADJ P+

LM2575SX-12/NOPB ACTIVE DDPAK/

TO-263 KTT 5 500 RoHS-Exempt

& Green SN Level-3-245C-168 HR -40 to 125 LM2575S

-12 P+

LM2575SX-15/NOPB ACTIVE DDPAK/

TO-263 KTT 5 500 RoHS-Exempt

& Green SN Level-3-245C-168 HR -40 to 125 LM2575S

-15 P+

LM2575SX-3.3/NOPB ACTIVE DDPAK/

TO-263 KTT 5 500 RoHS-Exempt

& Green SN Level-3-245C-168 HR -40 to 125 LM2575S

-3.3 P+

LM2575SX-5.0/NOPB ACTIVE DDPAK/

TO-263 KTT 5 500 RoHS-Exempt

& Green SN Level-3-245C-168 HR -40 to 125 LM2575S

-5.0 P+

PACKAGE OPTION ADDENDUM

www.ti.com 26-Feb-2021

Addendum-Page 4

Orderable Device Status

(1)

Package Type Package

Drawing Pins Package

Qty Eco Plan

(2)

Lead finish/

Ball material

(6)

MSL Peak Temp

(3)

Op Temp (°C) Device Marking

(4/5)

Samples

LM2575SX-ADJ NRND DDPAK/

TO-263 KTT 5 500 Non-RoHS

& Green Call TI Call TI -40 to 125 LM2575S

-ADJ P+

LM2575SX-ADJ/NOPB ACTIVE DDPAK/

TO-263 KTT 5 500 RoHS-Exempt

& Green SN Level-3-245C-168 HR -40 to 125 LM2575S

-ADJ P+

LM2575T-12 NRND TO-220 KC 5 45 Non-RoHS

& Green Call TI Call TI -40 to 125 LM2575T

-12 P+

LM2575T-12/LF03 ACTIVE TO-220 NDH 5 45 RoHS & Green SN Level-1-NA-UNLIM LM2575T

-12 P+

LM2575T-12/NOPB ACTIVE TO-220 KC 5 45 RoHS & Green SN Level-1-NA-UNLIM -40 to 125 LM2575T

-12 P+

LM2575T-15 NRND TO-220 KC 5 45 Non-RoHS

& Green Call TI Call TI -40 to 125 LM2575T

-15 P+

LM2575T-15/LF03 ACTIVE TO-220 NDH 5 45 RoHS & Green SN Level-1-NA-UNLIM LM2575T

-15 P+

LM2575T-15/NOPB ACTIVE TO-220 KC 5 45 RoHS & Green SN Level-1-NA-UNLIM -40 to 125 LM2575T

-15 P+

LM2575T-3.3/LF03 ACTIVE TO-220 NDH 5 45 RoHS & Green SN Level-1-NA-UNLIM LM2575T

-3.3 P+

LM2575T-3.3/NOPB ACTIVE TO-220 KC 5 45 RoHS & Green SN Level-1-NA-UNLIM -40 to 125 LM2575T

-3.3 P+

LM2575T-5.0 NRND TO-220 KC 5 45 Non-RoHS

& Green Call TI Call TI -40 to 125 LM2575T

-5.0 P+

LM2575T-5.0/LB03 NRND TO-220 NDH 5 45 Non-RoHS

& Green Call TI Call TI LM2575T

-5.0 P+

LM2575T-5.0/LF03 ACTIVE TO-220 NDH 5 45 RoHS & Green SN Level-1-NA-UNLIM LM2575T

-5.0 P+

LM2575T-5.0/NOPB ACTIVE TO-220 KC 5 45 RoHS & Green SN Level-1-NA-UNLIM -40 to 125 LM2575T

-5.0 P+

LM2575T-ADJ NRND TO-220 KC 5 45 Non-RoHS

& Green Call TI Call TI -40 to 125 LM2575T

-ADJ P+

LM2575T-ADJ/LB03 NRND TO-220 NDH 5 45 Non-RoHS

& Green Call TI Call TI LM2575T

-ADJ P+

LM2575T-ADJ/LF02 ACTIVE TO-220 NEB 5 45 RoHS & Green SN Level-1-NA-UNLIM LM2575T

-ADJ P+

LM2575T-ADJ/LF03 ACTIVE TO-220 NDH 5 45 RoHS & Green SN Level-1-NA-UNLIM LM2575T

PACKAGE OPTION ADDENDUM

www.ti.com 26-Feb-2021

Addendum-Page 5

Orderable Device Status

(1)

Package Type Package

Drawing Pins Package

Qty Eco Plan

(2)

Lead finish/

Ball material

(6)

MSL Peak Temp

(3)

Op Temp (°C) Device Marking

(4/5)

Samples

-ADJ P+

LM2575T-ADJ/NOPB ACTIVE TO-220 KC 5 45 RoHS & Green SN Level-1-NA-UNLIM -40 to 125 LM2575T

-ADJ P+

(1) The marketing status values are defined as follows:

ACTIVE: Product device recommended for new designs.

LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.

NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.

PREVIEW: Device has been announced but is not in production. Samples may or may not be available.

OBSOLETE: TI has discontinued the production of the device.

(2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance

do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may

reference these types of products as "Pb-Free".

RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.

Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of <=1000ppm threshold. Antimony trioxide based

flame retardants must also meet the <=1000ppm threshold requirement.

(3) MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.

(4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device.

(5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation

of the previous line and the two combined represent the entire Device Marking for that device.

(6) Lead finish/Ball material - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead finish/Ball material values may wrap to two

lines if the finish value exceeds the maximum column width.

Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information

provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and

continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.

TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.

In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.

TAPE AND REEL INFORMATION

*All dimensions are nominal

Device Package

Type Package

Drawing Pins SPQ Reel

Diameter

(mm)

Reel

Width

W1 (mm)

(mm) B0

(mm) K0

(mm) P1

(mm) W

(mm) Pin1

Quadrant

LM2575HVSX-15/NOPB DDPAK/

TO-263 KTT 5 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2

LM2575HVSX-3.3/NOPB DDPAK/

TO-263 KTT 5 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2

LM2575HVSX-5.0 DDPAK/

TO-263 KTT 5 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2

LM2575HVSX-5.0/NOPB DDPAK/

TO-263 KTT 5 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2

LM2575HVSX-ADJ DDPAK/

TO-263 KTT 5 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2

LM2575HVSX-ADJ/NOPB DDPAK/

TO-263 KTT 5 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2

LM2575MX-5.0/NOPB SOIC DW 24 1000 330.0 24.4 10.8 15.9 3.2 12.0 24.0 Q1

LM2575MX-ADJ/NOPB SOIC DW 24 1000 330.0 24.4 10.8 15.9 3.2 12.0 24.0 Q1

LM2575SX-12/NOPB DDPAK/

TO-263 KTT 5 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2

LM2575SX-15/NOPB DDPAK/

TO-263 KTT 5 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2

LM2575SX-3.3/NOPB DDPAK/

TO-263 KTT 5 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2

LM2575SX-5.0/NOPB DDPAK/ KTT 5 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2

PACKAGE MATERIALS INFORMATION

www.ti.com 14-Jul-2020

Pack Materials-Page 1

Device Package

Type Package

Drawing Pins SPQ Reel

Diameter

(mm)

Reel

Width

W1 (mm)

(mm) B0

(mm) K0

(mm) P1

(mm) W

(mm) Pin1

Quadrant

TO-263

LM2575SX-ADJ DDPAK/

TO-263 KTT 5 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2

LM2575SX-ADJ/NOPB DDPAK/

TO-263 KTT 5 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2

*All dimensions are nominal

Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm)

LM2575HVSX-15/NOPB DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0

LM2575HVSX-3.3/NOPB DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0

LM2575HVSX-5.0 DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0

LM2575HVSX-5.0/NOPB DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0

LM2575HVSX-ADJ DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0

LM2575HVSX-ADJ/NOPB DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0

LM2575MX-5.0/NOPB SOIC DW 24 1000 367.0 367.0 45.0

LM2575MX-ADJ/NOPB SOIC DW 24 1000 367.0 367.0 45.0

LM2575SX-12/NOPB DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0

LM2575SX-15/NOPB DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0

LM2575SX-3.3/NOPB DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0

LM2575SX-5.0/NOPB DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0

PACKAGE MATERIALS INFORMATION

www.ti.com 14-Jul-2020

Pack Materials-Page 2

Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm)

LM2575SX-ADJ DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0

LM2575SX-ADJ/NOPB DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0

PACKAGE MATERIALS INFORMATION

www.ti.com 14-Jul-2020

Pack Materials-Page 3

www.ti.com

PACKAGE OUTLINE

9.25

7.67

6.86

5.69

3.05

2.54

14.73

12.29

5X 1.02

0.64

4X 1.7

8.89

6.86

12.88

10.08

(6.275)

4.83

4.06 1.40

1.14

3.05

2.03

0.61

0.30

-3.963.71

6.8

2X (R1)

OPTIONAL

16.51

MAX

10.67

9.65

(4.25)

4215009/A 01/2017

TO-220 - 16.51 mm max heightKC0005A

TO-220

NOTES:

1. All controlling linear dimensions are in inches. Dimensions in brackets are in millimeters. Any dimension in brackets or parenthesis are for

reference only. Dimensioning and tolerancing per ASME Y14.5M.

2. This drawing is subject to change without notice.

3. Shape may vary per different assembly sites.

0.25 C A B

PIN 1 ID

(OPTIONAL)

OPTIONAL

CHAMFER

SCALE 0.850

NOTE 3

AAAA

www.ti.com

EXAMPLE BOARD LAYOUT

0.07 MAX

ALL AROUND

0.07 MAX

ALL AROUND (1.45)

(2)

(R0.05) TYP

4X (1.45)

4X (2)

5X ( 1.2) (1.7) TYP

(6.8)

FULL R

TYP

TO-220 - 16.51 mm max heightKC0005A

TO-220

4215009/A 01/2017

LAND PATTERN

NON-SOLDER MASK DEFINED

SCALE:12X

PKG

METAL

TYP

SOLDER MASK

OPENING, TYP

MECHANICAL DATA

NDH0005D

www.ti.com

MECHANICAL DATA

KTT0005B

www.ti.com

BOTTOM SIDE OF PACKAGE

TS5B (Rev D)

MECHANICAL DATA

NEB0005F

www.ti.com

MECHANICAL DATA

NEB0005B

www.ti.com

IMPORTANT NOTICE AND DISCLAIMER

TI PROVIDES TECHNICAL AND RELIABILITY DATA (INCLUDING DATASHEETS), DESIGN RESOURCES (INCLUDING REFERENCE

DESIGNS), APPLICATION OR OTHER DESIGN ADVICE, WEB TOOLS, SAFETY INFORMATION, AND OTHER RESOURCES “AS IS”

AND WITH ALL FAULTS, AND DISCLAIMS ALL WARRANTIES, EXPRESS AND IMPLIED, INCLUDING WITHOUT LIMITATION ANY

IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT OF THIRD

PARTY INTELLECTUAL PROPERTY RIGHTS.

These resources are intended for skilled developers designing with TI products. You are solely responsible for (1) selecting the appropriate

TI products for your application, (2) designing, validating and testing your application, and (3) ensuring your application meets applicable

standards, and any other safety, security, or other requirements. These resources are subject to change without notice. TI grants you

permission to use these resources only for development of an application that uses the TI products described in the resource. Other

reproduction and display of these resources is prohibited. No license is granted to any other TI intellectual property right or to any third party

intellectual property right. TI disclaims responsibility for, and you will fully indemnify TI and its representatives against, any claims, damages,

costs, losses, and liabilities arising out of your use of these resources.

TI’s products are provided subject to TI’s Terms of Sale (https:www.ti.com/legal/termsofsale.html) or other applicable terms available either

on ti.com or provided in conjunction with such TI products. TI’s provision of these resources does not expand or otherwise alter TI’s

applicable warranties or warranty disclaimers for TI products.IMPORTANT NOTICE

Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265