3.0A, 150kHz, Step-Down Switching Regulator LM2596
Feb. 2020 - Rev. 1.5.1 - 1 - HTC
FEATURES
3.3V, 5.0V, 12V, and Adjustable Output version
Adjustable Output Voltage range, 1.2V to 37V
±4% Max. Over Line and Load conditions
Guaranteed Output Current of 3A
Available in TO-263, TO-220 Packages
Requires Only 4 External Components
Excellent Line and Load Regulation Specifications
150kHz Fixed Frequency Internal Oscillator
TTL Shutdown Capability
Low Power Standby Mode, IQ typically 100mA
Thermal Shutdown and Current Limit Protection
Moisture Sensitivity Level 3
APPLICATION
Simple High-Eff ic iency Step-Down(Buck) Regulator
Efficien t Pr e-Regulator for Linear Regulators
On-Card Switching Regulators
Positive to Negative Converter(Buck-Boost)
Negative Step-Up Converters
Power Supply for Battery Chargers
DESCRIPTION
TO-263 PKG
TO-220 PKG
SOP8-PP PKG
ORDERING INFORMAT ION
Device Package
LM2596R-X.X TO-263-5L
LM2596T-X.X TO-220-5L
LM2596DP-X.X SOP-8PP
X.X = Output Voltage = 3.3, 5.0, 12, ADJ
The LM2596 series of regulators are monolithic integrated circuits ideally suited for easy and convenient
design of a step-down switching regulator (buck converter). All circuits of this series are capable of driving a
3.0A load with excellent line and load regulation. These devices are available in fixed output voltages of 3.3V,
5.0V,12V, and an adjustable output version. These regulators were designed to minimize the number of
external components to simplify the power supply design. Standard series of inductors optimized for use with
the LM2596 are offered by several different inductor manufacturers. Since the LM2596 converter is a switch-
mode power supply, its efficiency is significantly higher in comparison with popular three-terminal linear
regulators , es p ec ially with hig her input voltages. In many cas es, the power d is si pated is so lo w th at n o h eats ink
is required or its size could be reduced dramatically. A standard series of inductors optimized for use with the
LM2596 ar e available from several differ ent manuf acturers. T his feat ure greatl y sim plifies the desig n of switch-
mode power supplies. The LM2596 features include a guaranteed +/- 4% tolerance on output voltage within
specif ied input voltages a n d output load conditi ons, and +/-15% on th e osci llator f requenc y (+/- 2% o ver 0℃ to
125℃). Ext ernal s hutdown is inc luded , featurin g 80㎂ (t ypical) standb y current. Self-protection features incl ude
a two stage frequency reducing current limit for output switch and an over temperature shutdown for complete
protection under fault conditions.
1 5
1 5
1
4
3.0A, 150kHz, Step-Down Switching Regulator LM2596
Feb. 2020 - Rev. 1.5.1 - 2 - HTC
Ordering Information
VOUT Package Order No. Description Package Marking Status
ADJ
SOP-8PP LM2596DP-ADJ 3A, Adjustable, 150kHz, On/off LM2596-ADJ Active
TO-220-5L LM2596T-ADJ 3A, Adjustable, 150kHz, On/off LM2596-ADJ Active
TO-263-5L LM2596R-ADJ 3A, Adjustable, 150kHz, On/off LM2596-ADJ Active
3.3V
SOP-8PP LM2596DP-3.3 3A, Fixed, 150kHz, On/off LM2596-3.3 Contact Us
TO-220-5L LM2596T-3.3 3A, Fixed, 150kHz, On/off LM2596-3.3 Active
TO-263-5L LM2596R-3.3 3A, Fixed, 150kHz, On/off LM2596-3.3 Active
5.0V
SOP-8PP LM2596DP-5.0 3A, Fixed, 150kHz, On/off LM2596-5.0 Active
TO-220-5L LM2596T-5.0 3A, Fixed, 150kHz, On/off LM2596-5.0 Active
TO-263-5L LM2596R-5.0 3A, Fixed, 150kHz, On/off LM2596-5.0 Active
12V
SOP-8PP LM2596DP-12 3A, Fixed, 150kHz, On/off LM2596-12 Contact Us
TO-220-5L LM2596T-12 3A, Fixed, 150kHz, On/off LM2596-12 Active
TO-263-5L LM2596R-12 3A, Fixed, 150kHz, On/off LM2596-12 Active
3.0A, 150kHz, Step-Down Switching Regulator LM2596
Feb. 2020 - Rev. 1.5.1 - 3 - HTC
PIN CONFIGURATION
VOUT
GND
FEEDBACK
ON/OFF
VIN
VOUT
GND
FEEDBACK
ON/OFF
VIN
SOP8-PP TO220-5L TO263-5L
PIN DESCRIPTION
Package
Symbol Description
TO-220 5L
TO-263 5L SOP8-PP
1 1 VIN
This pin is the positive input supply for the LM2596 step–down
switching regulator. In order to minimize voltage transients and to
supply the switching currents needed by the regulator, a suitable
input bypass capacitor must be present.
2 2 VOUT
This is the emitter of the internal switch. The saturation voltage
Vsat of this output s witch is typica ll y 1.5 V. It sh ould be k ept in m ind
that the PCB area connected to this pin should be kept to a
minimum in order to minimiz e coupling to sensitive circuitry.
3 3 GND Circuit groun d pin.
4 4 FEEDBACK
This pin s enses reg ulated out put voltage to c omplete the feedbac k
loop. The signal is divided by the internal resistor divider network
R2, R1 and applied to the non–inverting input of the internal error
amplifier. In the Adjustable ve
rsion of the LM2596 switching
regulator this pin is the direct input of the error amplifier and the
resistor network R2, R1 is connected externally to allow
programming of the output voltage.
5 5 ON/OFF
It allo ws t he switching regulator circuit to b e shut dow n using logic
level signals, thus dropping the total input supply current to
approximately 80uA. The threshold voltage is typically 1.3V.
Applying a voltage above t his value (u p to +Vin) shuts the re gulator
off. If the voltage app li ed t o this p in is lower than 1. 3V or if this pi n is
left open, the regulator will be in the "on" condition.
- 6, 7, 8 N.C. No Connect.
* Exposed Pad of SOP8-PP package should be externally connected to GND.
Exposed
PAD
VIN 1
VOUT 2
GND 3
FEEDBACK 4
8 N/C
7 N/C
6 N/C
5 ON/OFF
3.0A, 150kHz, Step-Down Switching Regulator LM2596
Feb. 2020 - Rev. 1.5.1 - 4 - HTC
Typical Application (Fixe d Output Voltage Versions)
L1
33uH
Cout
220uF
D1
1N5824
Vout
Cin
680uF
Vin VIN
OUTPUT
FEEDBACK
ON/OFF GND
LM2596-5.0
Absolute Maximum Ratings
Rating Symbol Value UNIT
Maximum Supply Voltage Vin 45 V
On/Off Pin Input Voltage - -0.3V ≤ V ≤ +Vin V
Output Voltage to Ground (Steady-State) - -1.0 V
Power D is s ipat io n
SOP8-PP-8Lead
Thermal Resistance, Junction to Ambient
Thermal Resistance, Junction to Case
PD
θJA
Internally Limited
Contact us
Contact us
W
℃/W
℃
/W
TO-220-5Lead
Internally Limited
W
Thermal Resistance, Junction to Ambient
65
℃
/W
Thermal Resistance, Junction to Case θ
5 ℃/W
TO-263-5Lead
Internally Limited
W
Thermal Resistance, Junction to Ambient
70
℃
/W
Thermal Resistance, Junction to Case
5
℃
/W
Storage Temperature Range TSTG -60 to +150 ℃
Minimum ESD Rating (Human Body Model)
2
kV
Lead Temperature (Soldering, 10seconds) - 260 ℃
Maximum Junction Temperature TJ 150 ℃
3.0A, 150kHz, Step-Down Switching Regulator LM2596
Feb. 2020 - Rev. 1.5.1 - 5 - HTC
OPERATING RATINGS (Operating Ratings indicate condit ions for which the device is intended to be
functional, but do not guarantee specific performance limits. For guaranteed specifications, see the
Electrical Charact eristics.)
Rating Symbol Value. Unit
Operating Junction Temperature Range TJ -40 to +125 ℃
Supply Voltage Vin 40 V
ELECTRIC AL CH ARACTERISTI CS / SYSTEM PARAMETERS ([Note 1] Test Circuit Figure 2)
(Unless otherwise spec ified, Vin = 12V for the 3.3V, 5.0V, and Adjustable version, Vin = 25V for the 12V version. ILOAD = 500 mA. For typic al
values TJ = 2 5°C, for min/max values TJ is the operat i ng junction temperature range t hat applies [ Not e 2], unless otherwise noted. )
Characteristics Symbol Min TYP Max Unit
LM2596-3.3V ([Note 1] Test Circuit Fig u re 2)
Output Voltage (V in=12 V, ILOAD =0.5A, TJ=25℃) Vout 3.234 3.3 3.366 V
Output Voltage (6.0V≤Vin≤40V, 0.5A≤ILOAD≤3.0A Vout
V TJ=25℃
3.168 3.3 3.432
TJ=-40℃ ~ +125℃
3.135 - 3.465
Efficiency (Vin=12V, ILOAD=3.0A) η - 73 - %
LM2596-5.0V ([Note 1] Test Circuit Figure 2)
Output Voltage (V in=12 V, ILOAD=0.5A, TJ=25℃) Vout 4.9 5.0 5.1 V
Output Voltage (8.0V≤Vin≤40V, 0.5A≤ILOAD≤3.0A Vout
V TJ=25℃
4.8 5.0 5.2
TJ=-40℃ ~ +125℃
4.75 - 5.25
Efficiency (Vin=12V, ILOAD=3.0A) η - 80 - %
LM2596-12V ([Note 1] Test Circuit Figure 2)
Output Voltage (V in=25 V, ILOAD=0.5A, TJ=25℃) Vout 11.76 12 12.24 V
Output Voltage (15V≤Vin≤40V, 0.5A≤ILOAD≤3.0A Vout
V TJ=25℃
11.52 12 12.48
TJ= -40℃ ~ +125℃
11.4 - 12.6
Efficiency (Vin=12V, ILOAD=3.0A) η - 90 - %
LM2596-ADJ ([Note 1] Te st Ci r cu it Figure 2)
Feedback Voltage (Vin=12V, ILOAD=0.5A, TJ=25℃) Vout 1.217 1.23 1.243 V
Feedback Voltage(8.0V≤Vin≤40V, 0.5A≤ILOAD≤3.0A, Vout=5.0V) Vout
V TJ=25℃
1.193 1.23 1.267
TJ= -40℃ ~ +125℃
1.18 - 1.28
Efficiency (Vin=12V, ILOAD=3.0A, Vout=5.0V) η - 73 - %
3.0A, 150kHz, Step-Down Switching Regulator LM2596
Feb. 2020 - Rev. 1.5.1 - 6 - HTC
Characteristics
Symbol
Min
TYP
Max
Unit
All Output Voltage Versions
Feedback Bias Current (Vout=5.0V [Adj ustable Version Only]) Ib
nA
TJ=25℃ 11.52 12 12.48
TJ= 0 ~ +125℃ 11.4 - 12.6
Oscillat or Frequency Fosc
kHz
TJ=25℃ 127 150 173
TJ= 0 ~ +125℃ 110 - 173
Saturati on Voltage (Iout=3.0A [note 3]) Vsat
V
TJ=25℃ - 1.16 1.4
TJ= 0 ~ +125℃ - - 1.5
Max Duty Cycle ("0") [Note 4] DC - 100 - %
Current Limit (Peak Current [Note 3]) ICL
A
TJ=25℃ 3.6 4.5 6.9
TJ= 0 ~ +125℃ 3.4 - 7.5
Output Leakage Current [Note 5 and 6], TJ=25℃ IL
Output = 0V - - 25 µA
Output = -1.0V - 2 10 mA
Quiescent Current [Note 5] IQ
mA
TJ=25℃ - 5 -
TJ= 0 ~ +125℃ - - 10
Standby Quiescent Current (ON/OFF Pin = 5.0V ("off")) ISTBY
µA
TJ=25℃ - 80 200
TJ= 0 ~ +125℃ - - 250
ON/OFF Pin Logic Input Level (Test ci rcuit Fi gure 2)
V
Vout=0V VIH
TJ=25℃ 2.0 1.3 -
TJ= 0 ~ +125℃ 2.0 - -
Vout=Nominal Output Voltage VIL
TJ=25℃ - 1.3 0.6
TJ= 0 ~ +125℃ - - 0.6
ON/OFF Pin Input Current (Test Circuit Figure 2)
µA
VLOGIC = 2.5V (Regulator OFF) IIH - 5 15
VLOGIC = 0.5V (Regulator ON) IIL - 0.02 5.0
1. External components such as the catch diode, inductor, input and output capacitors can affect switching regulator system performance.
When the LM2596 is used as shown in the Figure 1 test circuit, system performance will be as shown in system parameters section .
2. Tested junction temperature range for the LM2596 : TLOW = –40°C THIGH = +125°C
3. Output (Pin 2) sourcing current. No diode, induct or or capacitor connected to output pin.
4. Feedback (Pin 4) removed from output and connected to 0 V.
5. Feedback (Pin 4) removed from output and connected to +12V for the Adjustable, 3.3V, and 5.0V versions, and '+25 V for the 12V versions,
to force the output transistor “off”.C195
6. Vin = 40 V.
3.0A, 150kHz, Step-Down Switching Regulator LM2596
Feb. 2020 - Rev. 1.5.1 - 7 - HTC
TYPICAL PERFORMANCE CHARACTERISTICS (Circuit of Figure 2)
3.0A, 150kHz, Step-Down Switching Regulator LM2596
Feb. 2020 - Rev. 1.5.1 - 8 - HTC
TYPICAL PERFORMANCE CHARACTERISTICS
(Circuit of Figure 2)
3.0A, 150kHz, Step-Down Switching Regulator LM2596
Feb. 2020 - Rev. 1.5.1 - 9 - HTC
Test Circuit and Layout Guidelines
CIN = 470㎌, 50V, COUT = 220㎌, 25V (Aluminum Electrolytic Nichicon "PL Series"
D1 = 5A, 40V Schottky Rectifier, IN5825
L1 = 68uH, L38
Cin = 470 ㎌, 50V, Cout = 220 ㎌, 35V (Aluminum Electrolytic Nichicon "PL Series"
D1 = 5A, 40V Schottky Rectifier, IN5825
L1 = 68uH, R1 = 1 ㏀, 1%, R2 = R1 x (Vout / Vref - 1)
As in any switching regulator, layout is very important. Rapidly switching currents associated with wiring
inductance ca n gen er ate v oltage tr ans ie nts whic h ca n c aus e pr ob lems. For minimal induc tance a nd ground lo ops,
the wires indicated by heavy lines should be wide printed circuit traces and should be kept as short as possible.
For best results, external components should be located as close to the switching lC as possible using ground
plane const ruc t ion or s in gle poi nt gro und in g. If open co r e induc tor s are us e d, s pecial care must be taken as to th e
location and positioning of this type of inductor. Allowing the inductor flux to intersect sensitive feedback, lC
ground path and COUT wiring can cause problems. When using the adjustable version, special care must be
taken as to the location of the feedback resistors and the associated wiring. Physically locate both resistors near
the IC, and route the wiring away from the inductor, especially an open core type of inductor.
3.0A, 150kHz, Step-Down Switching Regulator LM2596
Feb. 2020 - Rev. 1.5.1 - 10 - HTC
REVISION NOTICE
The description in this data sheet can be revised without any notice to describe its electrical characteristics
properly.