LM5067MMX-2/NOPB - Texas Instruments

GND

VCC

VEE SENSETIMER

UVLO/EN

GATE

OVLO

PGD

LM5067

PWR

OUT

LOAD

RSQ1

-48V

LM5067

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SNVS532C –OCTOBER 2007–REVISED MARCH 2013

Negative Hot Swap / Inrush Current Controller with Power Limiting

Check for Samples: LM5067

1FEATURES DESCRIPTION

The LM5067 negative hot swap controller provides

2• Wide operating range: -9V to -80V intelligent control of the power supply connections

• In-rush current limit for safe board insertion during insertion and removal of circuit cards from a

into live power sources live system backplane or other “hot” power sources.

• Programmable maximum power dissipation in The LM5067 provides in-rush current control to limit

system voltage droop and transients. The current limit

the external pass device and power dissipation in the external series pass N-

• Adjustable current limit Channel MOSFET are programmable, ensuring

• Circuit breaker function for severe over- operation within the Safe Operating Area (SOA). In

current events addition, the LM5067 provides circuit protection by

monitoring for over-current and over-voltage

• Adjustable under-voltage lockout (UVLO) and conditions. The POWER GOOD output indicates

hysteresis when the output voltage is close to the input voltage.

• Adjustable over-voltage lockout (OVLO) and The input under-voltage and over-voltage lockout

hysteresis levels and hysteresis are programmable, as well as

• Initial insertion timer allows ringing and the fault detection time. The LM5067-1 latches off

transients to subside after system connection after a fault detection, while the LM5067-2

automatically attempts restarts at a fixed duty cycle.

• Programmable fault timer avoids nuisance The LM5067 is available in a 10-pin VSSOP package

trips and a 14-pin SOIC package.

• Active high open drain POWER GOOD output

• Available in latched fault and automatic restart APPLICATIONS

versions • Server Backplane Systems

• In-Rush Current Limiting

PACKAGES • Solid State Circuit Breaker

• VSSOP-10 • Transient Voltage Protector

• SOIC-14 (Latched Fault Version) • Solid State Relay

• Under-voltage Lock-out

• Power Good Detector/Indicator

Typical Application

Figure 1. Negative Power Bus In-Rush and Fault Protection

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.

2All 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.

UVLO/EN

OVLO

PWR

VEE

VCC

N/C

OUT

N/C

GATE

SENSE

PGD

TIMER

N/C

UVLO/EN

OVLO

PWR

VEE TIMER

PGD

OUT

VCC

GATE

SENSE

LM5067

SNVS532C –OCTOBER 2007–REVISED MARCH 2013

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Connection Diagram

NOTE: N/C Pins are internally not connected to anything.

Figure 2. Top View Figure 3. Top View

10-Lead VSSOP 14-Lead SOIC

PIN DESCRIPTIONS

Pin No. Name Description Applications Information

VSSOP-10 SOIC-14

1 1 VCC Positive supply Connect to system ground through a resistor. Connect a bypass capacitor to

input VEE. The voltage from VCC to VEE is nominally 13V set by an internal zener

diode.

2 3 UVLO/EN Under-voltage An external resistor divider from the system input voltage sets the under-voltage

lockout turn-on threshold. The enable threshold at the pin is 2.5V above VEE. An internal

22 µA current source provides hysteresis. This pin can be used for remote enable

and disable.

3 4 OVLO Over-voltage An external resistor divider from the system input voltage sets the over-voltage

lockout turn-off threshold. The disable threshold at the pin is 2.5V above VEE. An internal

22 µA current source provides hysteresis.

4 5 PWR Power limit set An external resistor at this pin, in conjunction with the current sense resistor (RS),

sets the maximum power dissipation in the external series pass MOSFET.

5 6 VEE Negative supply Connect to the system negative supply voltage (typically -48V).

input

6 8 TIMER Timing capacitor An external capacitor at this pin sets the insertion time delay and the fault timeout

period. The capacitor also sets the restart timing of the LM5067-2.

7 9 SENSE Current sense The voltage across the current sense resistor (RS) is measured from VEE to this

input pin. If the voltage across RSreaches 50 mV the load current is limited and the

fault timer activates.

8 10 GATE Gate drive output Connect to the external N-channel MOSFET’s gate.

9 12 OUT Output feedback Connect to the external MOSFET’s drain. Internally used to determine the

MOSFET VDS voltage for power limiting, and to control the PGD output pin.

10 14 PGD Power Good An open drain output capable of sustaining 80V when off. When the external

indicator MOSFET VDS decreases below 1.23V the PGD pin switches high. When the

external MOSFET VDS increases above ≊2.5V the PGD pin switches low.

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.

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SNVS532C –OCTOBER 2007–REVISED MARCH 2013

Absolute Maximum Ratings (1)

Current into VCC (100 µs pulse) 100 mA

OUT, PGD to VEE -0.3V to 100V

UVLO, OVLO to VEE -0.3V to 17V

SENSE to VEE -0.3V to +0.3V

ESD Rating, Human Body Model(2) 2kV

Storage Temperature -65°C to +150°C

Junction Temperature +150°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 specifications and conditions see the

Electrical Characteristics.

(2) The human body model is a 100 pF capacitor discharged through a 1.5 kΩresistor into each pin.

Operating Ratings

Current into VCC (1) 2 mA (min)

OUT Voltage above VEE 0V to 80V

PGD Off Voltage above VEE 0V to 80V

Junction Temperature −40°C to +125°C

(1) Maximum continuous current into VCC is limited by power dissipation and die temperature. See the Thermal Considerations section.

Electrical Characteristics

Limits in standard type are for TJ= 25°C only; limits in boldface type apply over the junction temperature (TJ) range of -40°C

to +125°C. Minimum and Maximum limits are specified through test, design, or statistical correlation. Typical values represent

the most likely parametric norm at TJ= 25°C, and are provided for reference purposes only. Unless otherwise stated the

following conditions apply: ICC = 2 mA, OUT Pin = 48V above VEE, all voltages are with respect to VEE. See (1).

Symbol Parameter Conditions Min Typ Max Unit

Input

VZOperating voltage, VCC – VEE ICC = 2 mA, UVLO = 5V 12.3 13 13.6 V

5 5

ICC-EN Internal operating current, enabled VCC-VEE = 11V, 0.8 1mA

UVLO = 5V

ICC-DIS Internal operating current, disabled VCC-VEE = 11V, 480 660 µA

UVLO = 2V

PORIT Threshold voltage to start insertion timer VCC-VEE increasing 7.7 8.2 V

POREN Threshold voltage to enable all functions VCC-VEE increasing 8.4 8.7 V

POREN-HYS POREN hysteresis VCC-VEE decreasing 125 mV

OUT Pin

IOUT-EN OUT bias current, enabled OUT = VEE, Normal operation 0.1 µA

IOUT-DIS OUT bias current, disabled Disabled, OUT = VEE + 48V 50

SENSE Pin

ISNS-EN SENSE bias current, enabled OUT = VEE, Normal operation -6 µA

ISNS-DIS SENSE bias current, disabled Disabled, OUT = VEE + 48V -50

UVLO, OVLO Pins

UVLOTH UVLO threshold 2.45 2.5 2.55 V

UVLOHYS UVLO hysteresis current UVLO = VEE + 2V 10 22 34 µA

UVLODEL UVLO delay Delay to GATE high 26 µs

Delay to GATE low 12 µs

UVLOBIAS UVLO bias current UVLO = VEE + 5V 1µA

OVLOTH OVLO threshold 2.43 2.5 2.57 V

OVLOHYS OVLO hysteresis current OVLO = VEE+2.8V -34 -22 -10 µA

(1) Current out of a pin is indicated as a negative value.

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SNVS532C –OCTOBER 2007–REVISED MARCH 2013

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Electrical Characteristics (continued)

Limits in standard type are for TJ= 25°C only; limits in boldface type apply over the junction temperature (TJ) range of -40°C

to +125°C. Minimum and Maximum limits are specified through test, design, or statistical correlation. Typical values represent

the most likely parametric norm at TJ= 25°C, and are provided for reference purposes only. Unless otherwise stated the

following conditions apply: ICC = 2 mA, OUT Pin = 48V above VEE, all voltages are with respect to VEE. See (1).

Symbol Parameter Conditions Min Typ Max Unit

OVLODEL OVLO delay Delay to GATE high 26 µs

Delay to GATE low 12 µs

OVLOBIAS OVLO bias current OVLO = VEE + 2.4V 1µA

Gate Control (GATE Pin)

IGATE Source current Normal Operation -72 -52 -32 µA

Sink current UVLO < 2.5V 1.9 2.2 2.68 mA

SENSE - VEE =150 mV or 45 110 200

VCC - VEE < PORIT, VGATE = 5V

VGATE Gate output voltage in normal operation GATE-VEE voltage VZV

Current Limit

VCL Threshold voltage SENSE - VEE voltage 44 50 56 mV

tCL Response time SENSE - VEE stepped from 0 mV 25 µs

to 80 mV

Circuit Breaker

VCB Threshold voltage SENSE - VEE voltage 70 100 130 mV

tCB Response time SENSE - VEE stepped from 0 mV 0.65 1.0 µs

to 150 mV, time to GATE low, no

load

Power Limit (PWR Pin)

PWRLIM Power limit sense voltage (SENSE - VEE) OUT - SENSE = 24V, RPWR = 75 16.5 22 27.5 mV

kΩ

IPWR PWR pin current VPWR = 2.5V -23 µA

Timer (TIMER Pin)

VTMRH Upper threshold 3.76 44.16 V

VTMRL Lower threshold Restart cycles (LM5067-2) 1.18 1.25 1.32 V

End of 8th cycle (LM5067-2) 0.3 V

Re-enable threshold (LM5067-1) 0.3 V

ITIMER Insertion time current TIMER pin = 2V -9.5 -6 -2.5 µA

Sink current, end of insertion time TIMER pin = 2V 1.2 1.55 1.9 mA

Fault detection current TIMER pin = 2V -140 -85 -44 µA

Sink current, end of fault time 0.9 2.5 4.25 µA

DCFAULT Fault Restart Duty Cycle LM5067-2 0.5 %

tFAULT Fault to GATE low delay TIMER pin reaches 4.0V 15 µs

Power Good (PGD Pin)

PGDTH Threshold measured at OUT - SENSE Decreasing 1.16 1.23 1.28 V

2 5

Increasing, relative to decreasing 1.14 1.25 1.32

threshold 35

PGDVOL Output low voltage ISINK = 2 mA 60 150 mV

PGDIOH Off leakage current VPGD = 80V 5µA

Thermal Resistance(2)

θJA Junction to Ambient VSSOP package 94 °C/W

θJC Junction to Case VSSOP package 44 °C/W

θJA Junction to Ambient SOIC-14 Package 90 °C/W

(2) Tested on a 4 layer JEDEC board with 2 vias under the package. See JEDEC standards JESD51-7 and JESD51-3. See the Thermal

Considerations section.

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SNVS532C –OCTOBER 2007–REVISED MARCH 2013

Electrical Characteristics (continued)

Limits in standard type are for TJ= 25°C only; limits in boldface type apply over the junction temperature (TJ) range of -40°C

to +125°C. Minimum and Maximum limits are specified through test, design, or statistical correlation. Typical values represent

the most likely parametric norm at TJ= 25°C, and are provided for reference purposes only. Unless otherwise stated the

following conditions apply: ICC = 2 mA, OUT Pin = 48V above VEE, all voltages are with respect to VEE. See (1).

Symbol Parameter Conditions Min Typ Max Unit

θJC Junction to Case SOIC-14 Package 27 °C/W

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Typical Performance Characteristics

Unless otherwise specified the following conditions apply: TJ= 25°C.

ICC ICC

vs. vs.

Operating Voltage - Disabled Operating Voltage - Enabled

Operating Voltage SENSE Pin Current

vs. vs.

ICC System Voltage

OUT Pin Current GATE Source Current

vs. vs.

System Voltage Operating Voltage

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SNVS532C –OCTOBER 2007–REVISED MARCH 2013

Typical Performance Characteristics (continued)

Unless otherwise specified the following conditions apply: TJ= 25°C.

GATE Pull-Down Current, Circuit Breaker PGD Low Voltage

vs. vs.

GATE Voltage Sink Current

MOSFET Power Dissipation Limit UVLO & OVLO Hysteresis Current

vs. vs.

RPWR and RSTemperature

UVLO, OVLO Threshold Voltage VZOperating Voltage

vs. vs.

Temperature Temperature

Product Folder Links: LM5067

-40

SENSE Pin ± VEE Pin

POWER LIMIT THRESHOLD (mV)

-20 0 20 40 60 80 100 120

RPWR = 75k, VEE = -24V

JUNCTION TEMPERATURE ( C)

LM5067

SNVS532C –OCTOBER 2007–REVISED MARCH 2013

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Typical Performance Characteristics (continued)

Unless otherwise specified the following conditions apply: TJ= 25°C.

Current Limit Threshold Circuit Breaker Threshold

vs. vs.

Temperature Temperature

Power Limit Threshold Gate Source Current

vs. vs.

Temperature Temperature

GATE Pull-Down Current, Circuit Breaker PGD Pin Low Voltage

vs. vs.

Temperature Temperature

Product Folder Links: LM5067

Upper Restart Threshold

Lower Restart Threshold

Lower Reset Threshold

-40

JUNCTION TEMPERATURE (°C)

-20 0 20 40 60 80 100 125

TIMER PIN THRESHOLDS (V)

1.4

1.2

0.4

0.2

3.9

4.1

LM5067

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SNVS532C –OCTOBER 2007–REVISED MARCH 2013

Typical Performance Characteristics (continued)

Unless otherwise specified the following conditions apply: TJ= 25°C.

POREN Threshold TIMER Pin Thresholds

vs. vs.

Temperature Temperature

TIMER Pin Fault Detection Current

vs.

Temperature

Product Folder Links: LM5067

GND

LOAD

VCC

VEE SENSETIMER GATE

OVLO

PGD

LM5067

PWR

OUT

RPG

RIN

CIN

RPWR

VSYS

(-48V)

UVLO /EN

GATE

Fault

Timer

1.25V

TIMER

1.23V/

2.5V

Current Limit

Threshold

8.4/8.3V Enable POR

TIMER AND GATE

LOGIC CONTROL

Power Limit

Threshold

Gate

Control

1.55 mA

End

Insertion

Time

0.3V 7.7V

Vcc

Insertion Timer POR

110

VEE

SENSE

OUT

PWR

OVLO

UVLO/EN

Insertion

Timer

Fault

Discharge

PGD

Vcc

50 mV

2.2 mA

4.0V

2.5V

23 PA

22 PA

2.5 PA

85 PA

6 PA

52 PA

VDS

1 M:

13V

Vcc

VZVee

VCC

Vee

Current Limit

Power Limit

Control

Vcc

LM5067

All voltages are with respect to VEE

LM5067

SNVS532C –OCTOBER 2007–REVISED MARCH 2013

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BLOCK DIAGRAM

Figure 4. Basic Application Circuit

Product Folder Links: LM5067

Load

VCC

GND

BACKPLANE

PGD

OUT

LIVE

GATESENSEVEE

VSYS

RIN

LM5067

-48V

PLUG-IN BOARD

CIN

LM5067

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SNVS532C –OCTOBER 2007–REVISED MARCH 2013

FUNCTIONAL DESCRIPTION

The LM5067 is designed to control the in-rush current to the load upon insertion of a circuit card into a live

backplane or other “hot” power source, thereby limiting the voltage sag on the backplane’s supply voltage, and

the dV/dt of the voltage applied to the load. Effects on other circuits in the system are minimized, preventing

possible unintended resets. During the system power up, the maximum power dissipation in the series pass

device is limited to a safe value within the device’s Safe Operating Area (SOA). After the system power up is

complete, the LM5067 monitors the load for excessive currents due to a fault or short circuit at the load. Limiting

the load current and/or the power in the external MOSFET for an extended period of time results in the shutdown

of the series pass MOSFET. After a fault event, the LM5067-1 latches off until the circuit is re-enabled by

external control, while the LM5067-2 automatically restarts with defined timing. The circuit breaker function

quickly switches off the series pass device upon detection of a severe over-current condition caused by, e.g. a

short circuit at the load. The Power Good (PGD) output pin indicates when the output voltage is close to the

normal operating value. Programmable under-voltage lock-out (UVLO) and over-voltage lock-out (OVLO) circuits

shut down the LM5067 when the system input voltage is outside the desired operating range. The typical

configuration of a circuit card with LM5067 hot swap protection is shown in Figure 5.

Figure 5. LM5067 Application

The LM5067 can be used in a variety of applications, other than plug-in boards, to monitor for excessive load

current, provide transient protection, and ensuring the voltage to the load is within preferred limits. The circuit

breaker function protects the system from a sudden short circuit at the load. Use of the UVLO/EN pin allows the

LM5067 to be used as a solid state relay. The PGD output provides a status indication of the voltage at the load

relative to the input system voltage.

Power Up Sequence

The system voltage range of the LM5067 is -9V to -80V, with a transient capability to -100V. Referring to the

Block Diagram,Figure 4, and Figure 6, as the system voltage (VSYS) initially increases from zero, the external N-

channel MOSFET (Q1) is held off by an internal 110 mA pull-down current at the GATE pin. The strong pull-

down current at the GATE pin prevents an inadvertent turn-on as the MOSFET’s gate-to-drain (Miller)

capacitance is charged. When the operating voltage of the LM5067 (VCC – VEE) reaches the PORIT threshold

(7.7V) the insertion timer starts. During the insertion time, the capacitor at the TIMER pin (CT) is charged by a 6

µA current source, and Q1 is held off by a 2.2 mA pull-down current at the GATE pin regardless of the system

voltage. The insertion time delay allows ringing and transients at VSYS to settle before Q1 can be enabled. The

insertion time ends when the TIMER pin voltage reaches 4.0V above VEE, and CTis then quickly discharged by

an internal 1.5 mA pull-down current. After the insertion time, the LM5067 control circuitry is enabled when the

operating voltage reaches the POREN threshold (8.4V). As VSYS continues to increase, the LM5067 operating

voltage is limited at ≊13V by an internal zener diode. The remainder of the system voltage is dropped across the

input resistor RIN.

Product Folder Links: LM5067

TIMER Pin

Load

Current

PGD

UVLO

Limiting Normal Operation

GATE Pin

Insertion Time

Operating

Voltage

Output

Voltage

VEE

All waveforms and voltages are with respect to VEE

except System Input Voltage and Output Voltage.

2.5 PA

85PA

52PA source

2.2 mA pull-down

6 PA

1.25V

ILIMIT

VSYS

pull-down

110mA

VSYS

PORIT

System

Input

Voltage

(VCC ±

VEE)

LM5067

(OUT Pin)

In-rush

LM5067

SNVS532C –OCTOBER 2007–REVISED MARCH 2013

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The GATE pin switches on Q1 when VSYS exceeds the UVLO threshold (UVLO pin >2.5V above VEE). If VSYS

exceeds the UVLO threshold at the end of the insertion time, Q1 is switched on at that time. The GATE pin

sources 52 µA to charge Q1’s gate capacitance. The maximum gate-to-source voltage of Q1 is limited by the

LM5067’s operating voltage (VZ) to approximately 13V. During power up, as the voltage at the OUT pin increases

in magnitude with respect to Ground, the LM5067 monitors Q1’s drain current and power dissipation. In-rush

current limiting and/or power limiting circuits actively control the current delivered to the load. During the in-rush

limiting interval (t2 in Figure 6) an internal current source charges CTat the TIMER pin. When the load current

reduces from the limiting value to a value determined by the load the in-rush limiting interval is complete and CT

is discharged. The PGD pin switches high when the voltage at the OUT pin reaches to within 1.25V of the

voltage at the SENSE pin.

If the TIMER pin voltage reaches 4.0V before in-rush current limiting or power limiting ceases (during t2), a fault

is declared and Q1 is turned off. See Fault Timer and Restart for a complete description of the fault mode.

Figure 6. Power Up Sequence (Current Limit only)

Operating Voltage

The LM5067 operating voltage is the voltage from VCC to VEE. The maximum operating voltage is set by an

internal 13V zener diode. With the IC connected as shown in Figure 4, the LM5067 controller operates in the

voltage range between VEE and VEE+13V. The remainder of the system voltage is dropped across the input

resistor RIN, which must be selected to pass at least 2 mA into the LM5067 at the minimum system voltage.

Product Folder Links: LM5067

52 PA

GATE

VCC

SENSE

Insertion time

2.2mA Fault

Current Limit

Control Gate

Control

VEE OUT

VEE

System Gnd

Gate

Charge

VSYS

Power Limit

110 mA

Initial Hold-down

UVLO/OVLO

CIN

RIN

Circuit Breaker/

LM5067

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SNVS532C –OCTOBER 2007–REVISED MARCH 2013

Gate Control

The external N-channel MOSFET is turned on when the GATE pin sources 52 µA to enhance the gate. During

normal operation (t3 in Figure 6) Q1’s gate is held charged to approximately 13V above VEE, typically within 20

mV of the voltage at VCC. If the maximum VGS rating of Q1 is less than 13V, a lower voltage external zener

diode must be added between the GATE and SENSE pins. The external zener diode must have a forward

current rating of at least 110 mA.

When the system voltage is initially applied (before the operating voltage reaches the PORIT threshold), the

GATE pin is held low by a 110 mA pull-down current. The pull-down current helps prevent an inadvertent turn-on

of the MOSFET through its drain-gate capacitance as the applied system voltage increases.

During the insertion time (t1 in Figure 6) the GATE pin is held low by a 2.2 mA pull-down current. This maintains

Q1 in the off-state until the end of t1, regardless of the voltage at VCC and UVLO.

Following the insertion time, during t2 in Figure 6, the gate voltage of Q1 is modulated to keep the current or

Q1’s power dissipation level from exceeding the programmed levels. Current limiting and power limiting are

considered fault conditions, during which the voltage on the TIMER pin capacitor increases. If the current and

power limiting cease before the TIMER pin reaches 4V the TIMER pin capacitor is discharged, and the circuit

enters normal operation. See Fault Timer and Restart for details on the fault timer.

If the system input voltage falls below the UVLO threshold, or rises above the OVLO threshold, the GATE pin is

pulled low by the 2.2 mA pull-down current to switch off Q1.

Figure 7. Gate Control

Current Limit

The current limit threshold is reached when the voltage across the sense resistor RS(SENSE to VEE) reaches

50 mV. In the current limiting condition, the GATE voltage is controlled to limit the current in MOSFET Q1. While

the current limit circuit is active, the fault timer is active as described in the Fault Timer & Restart section. If the

load current reduces below the current limit threshold before the end of the Fault Timeout Period, the LM5067

resumes normal operation. For proper operation, the RSresistor value should be no larger than 100 mΩ.

Product Folder Links: LM5067

Restart

Control

VCC

OVLO

VEE

System Gnd VEE

SENSE

VSYS

CIN

RIN

UVLO/EN

LM5067-1

LM5067

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Circuit Breaker

If the load current increases rapidly (e.g., the load is short-circuited) the current in the sense resistor (RS) may

exceed the current limit threshold before the current limit control loop is able to respond. If the current exceeds

approximately twice the current limit threshold (100 mV/RS), Q1’s gate is quickly pulled down by the 110 mA pull-

down current at the GATE pin, and a Fault Timeout Period begins. When the voltage across RSfalls below 100

mV the 110 mA pull-down current at the GATE pin is switched off, and the gate voltage of Q1 is then determined

by the current limit or the power limit functions. If the TIMER pin reaches 4.0V before the current limiting or

power limiting condition ceases, Q1 is switched off by the 2.2 mA pull-down current at the GATE pin as

described in the Fault Timer & Restart section.

Power Limit

An important feature of the LM5067 is the MOSFET power limiting. The Power Limit function can be used to

maintain the maximum power dissipation of MOSFET Q1 within the device SOA rating. The LM5067 determines

the power dissipation in Q1 by monitoring its drain-source voltage (OUT to SENSE), and the drain current

through the sense resistor (SENSE to VEE). The product of the current and voltage is compared to the power

limit threshold programmed by the resistor at the PWR pin. If the power dissipation reaches the limiting threshold,

the GATE voltage is modulated to reduce the current in Q1, and the fault timer is active as described in the Fault

Timer & Restart section.

Fault Timer and Restart

When the current limit or power limit threshold is reached during turn-on or as a result of a fault condition, the

gate-to-source voltage of Q1 is modulated to regulate the load current and power dissipation in Q1. When either

limiting function is active, an 85 µA fault timer current source charges the external capacitor (CT) at the TIMER

pin as shown in Figure 9 (Fault Timeout Period). If the fault condition subsides before the TIMER pin reaches

4.0V, the LM5067 returns to the normal operating mode and CTis discharged by the 2.5 µA current sink. If the

TIMER pin reaches 4.0V during the Fault Timeout Period, Q1 is switched off by a 2.2 mA pull-down current at

the GATE pin. The subsequent restart procedure depends on which version of the LM5067 is in use.

The LM5067-1 latches the GATE pin low at the end of the Fault Timeout Period, and CTis discharged by the 2.5

µA fault current sink. The GATE pin is held low until a power up sequence is externally initiated by cycling the

input voltage (VSYS), or momentarily pulling the UVLO/EN pin within 2.5V of VEE with an open-collector or open-

drain device as shown in Figure 8. The voltage across CTmust be <0.3V for the restart procedure to be effective.

Figure 8. Latched Fault Restart Control

The LM5067-2 provides an automatic restart sequence which consists of the TIMER pin cycling between 4.0V

and 1.25V seven times after the Fault Timeout Period, as shown in Figure 9. The period of each cycle is

determined by the 85 µA charging current, and the 2.5 µA discharge current, and the value of the capacitor CT.

When the TIMER pin reaches 0.3V during the eighth high-to-low ramp, the 52 µA current source at the GATE pin

turns on Q1. If the fault condition is still present, the Fault Timeout Period and the restart cycle repeat.

Product Folder Links: LM5067

ILIMIT

Load

Current

GATE

TIMER

Pin 1 2 3 7 8

2.2 mA

pulldown

Fault Timeout

Period

0.3V

Fault

Detection

tRESTART

1.25V

85PA

52 PA

Gate Charge

All voltages are with respect to VEE

2.5 PA

LM5067

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SNVS532C –OCTOBER 2007–REVISED MARCH 2013

Figure 9. Restart Sequence (LM5067-2)

Under-Voltage Lock-Out (UVLO)

The series pass MOSFET (Q1) is enabled when the input supply voltage (VSYS) is within the operating range

defined by the programmable under-voltage lockout (UVLO) and over-voltage lock-out (OVLO) levels. Typically

the UVLO level at VSYS is set with a resistor divider (R1-R3) as shown in Figure 4. When VSYS is less than the

UVLO level, the internal 22 µA current sink at UVLO/EN is enabled, the current source at OVLO is off, and Q1 is

held off by the 2.2 mA pull-down current at the GATE pin. VSYS reaches its UVLO level when the voltage at the

UVLO/EN pin reaches 2.5V above VEE. Upon reaching the UVLO level, the 22 µA current sink at the UVLO/EN

pin is switched off, increasing the voltage at the pin, providing hysteresis for this threshold. With the UVLO/EN

pin above 2.5V, Q1 is switched on by the 52 µA current source at the GATE pin.

See Application Information for a procedure to calculate the values of the threshold setting resistors (R1-R3). The

minimum possible UVLO level can be set by connecting the UVLO/EN pin to VCC. In this case Q1 is enabled

when the operating voltage (VCC – VEE) reaches the POREN threshold (8.4V).

Over-Voltage Lock-Out (OVLO)

The series pass MOSFET (Q1) is enabled when the input supply voltage (VSYS) is within the operating range

defined by the programmable under-voltage lockout (UVLO) and over-voltage lock-out (OVLO) levels. Typically

the OVLO level at VSYS is set with a resistor divider (R1-R3) as shown in Figure 4. If VSYS raises the OVLO pin

voltage more than 2.5V above VEE Q1 is switched off by the 2.2 mA pull-down current at the GATE pin, denying

power to the load. When the OVLO pin is above 2.5V, the internal 22 µA current source at OVLO is switched on,

raising the voltage at OVLO and providing threshold hysteresis. When the voltage at the OVLO pin is reduced

below 2.5V the 22 µA current source is switched off, and Q1 is enabled. See Application Information for a

procedure to calculate the threshold setting resistor values.

Shutdown/Enable Control

See Application Information for a description of how to use the UVLO/EN pin and/or the OVLO pin for remote

shutdown and enable control of the LM5067.

Power Good Pin

The Power Good output indicator pin (PGD) is connected to the drain of an internal N-channel MOSFET. An

external pull-up resistor is required at PGD to an appropriate voltage to indicate the status to downstream

circuitry. The off-state voltage at the PGD pin must be more positive than VEE, and can be up to 80V above VEE

with transient capability to 100V. PGD is switched high at the end of the turn-on sequence when the voltage from

OUT to SENSE (the external MOSFET’s VDS) decreases below 1.23V. PGD switches low if the MOSFET’s VDS

increases past 2.5V, if the system input voltage goes below the UVLO threshold or above the OVLO threshold,

or if a fault is detected. The PGD output is high when the operating voltage (VCC-VEE) is less than 2V.

Product Folder Links: LM5067

72026)(7¶6

SOURCE

HIGH CURRENT PATH

VEE

SENSE

RESISTOR

FROM

SYSTEM

INPUT

VOLTAGE

LM5067

RS = 50 mV

ILIM

LM5067

SNVS532C –OCTOBER 2007–REVISED MARCH 2013

www.ti.com

APPLICATION INFORMATION (REFER TO FIGURE 4)

RIN, CIN

The LM5067 operating voltage is determined by an internal 13V shunt regulator which receives its current from

the system voltage via RIN. When the system voltage exceeds 13V, the LM5067 operating voltage (VCC – VEE)

is between VEE and VEE+13V. The remainder of the system voltage is dropped across the input resistor RIN,

which must be selected to pass at least 2 mA into the LM5067 at the minimum system voltage. The resistor’s

power rating must be selected based on the power dissipation at maximum system voltage, calculated from:

PRIN = (VSYS(max) – 13V)2/RIN (1)

CURRENT LIMIT, RS

The LM5067 monitors the current in the external MOSFET (Q1) by measuring the voltage across the sense

resistor (RS), connected from SENSE to VEE. The required resistor value is calculated from:

where

• ILIM is the desired current limit threshold (2)

When the voltage across RSreaches 50 mV, the current limit circuit modulates the gate of Q1 to regulate the

current at ILIM. While the current limiting circuit is active, the fault timer is active as described in the Fault Timer &

Restart section. For proper operation, RSmust be no larger than 100 mΩ.

While the maximum load current in normal operation can be used to determine the required power rating for

resistor RS, basing it on the current limit value provides a more reliable design since the circuit can operate near

the current limit threshold continuously. The resistor’s surge capability must also be considered since the circuit

breaker threshold is approximately twice the current limit threshold. Connections from RSto the LM5067 should

be made using Kelvin techniques. In the suggested layout of Figure 10 the small pads at the upper corners of the

sense resistor connect only to the sense resistor terminals, and not to the traces carrying the high current. With

this technique, only the voltage across the sense resistor is applied to VEE and SENSE, eliminating the voltage

drop across the high current solder connections.

Figure 10. Sense Resistor Connections

POWER LIMIT THRESHOLD

The LM5067 determines the power dissipation in the external MOSFET (Q1) by monitoring the drain current (the

current in RS), and the VDS of Q1 (OUT to SENSE pins). The resistor at the PWR pin (RPWR) sets the maximum

power dissipation for Q1, and is calculated from the following equation:

Product Folder Links: LM5067

tON = -(RL x CL) x In (ILIM x RL) - VSYS

(ILIM x RL)

VCC PGD

OUT

GND

GATESENSEVEE

VEE

LM5067

CIN

RIN

VSYS

tON =VSYS x CL

ILIM

LM5067

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SNVS532C –OCTOBER 2007–REVISED MARCH 2013

RPWR = 1.42 x 105x RSx PFET(LIM)

where

• PFET(LIM) is the desired power limit threshold for Q1

• RSis the current sense resistor described in the Current Limit section (3)

For example, if RSis 10 mΩ, and the desired power limit threshold is 60W, RPWR calculates to 85.2 kΩ. If Q1’s

power dissipation reaches the power limit threshold, Q1’s gate is modulated to control the load current, keeping

Q1’s power from exceeding the threshold. For proper operation of the power limiting feature, RPWR must be ≤150

kΩ. While the power limiting circuit is active, the fault timer is active as described in the Fault Timer & Restart

section. Typically, power limit is reached during startup, or when the VDS of Q1 increases due to a severe

overload or short circuit.

The programmed maximum power dissipation should have a reasonable margin relative to the maximum power

defined by the SOA chart if the LM5067-2 is used since the FET will be repeatedly stressed during fault restart

cycles. The FET manufacturer should be consulted for guidelines. The PWR pin can be left open if the

application does not require use of the power limit function.

TURN-ON TIME

The output turn-on time depends on whether the LM5067 operates in current limit only, or in both power limit and

current limit, during turn-on.

A) Turn-on with current limit only: If the current limit threshold is less than the current defined by the power

limit threshold at maximum VDS the circuit operates only at the current limit threshold during turn-on. Referring to

Figure 13a, as the drain current reaches ILIM, the gate-to-source voltage is controlled at VGSL to maintain the

current at ILIM. As the output voltage reaches its final value (VDS ≊0V) the drain current reduces to the value

defined by the load, and the gate is charged to approximately 13V (VGATE). The time for the OUT pin voltage to

transition from zero volts to VSYS is equal to:

where

• CLis the load capacitance (4)

For example, if VSYS = -48V, CL= 1000 µF, and ILIM = 1A, tON calculates to 48 ms. The maximum instantaneous

power dissipated in the MOSFET is 48W. This calculation assumes the time from t1 to t2 in Figure 13a is small

compared to tON, and the load does not draw any current until after the output voltage has reached its final value,

and PGD switches high (Figure 11).

Figure 11. No Load Current During Turn-on

If the load draws current during the turn-on sequence (Figure 12), the turn-on time is longer than the above

calculation, and is approximately equal to:

where

Product Folder Links: LM5067

Drain Current

00t2 t3

a) Current Limit Only

VSYS VDS

ILIM

VGATE

VGSL

VTH tON

Source Voltage-toGate-

b) Power Limit and Current Limit

VDS

Drain Current

tON

VSYS

ILIM

VGATE

VGSL

VTH

Source Voltage-toGate-

tON = CL x VSYS2

2 x PFET(LIM)

CL x PFET(LIM)

2 x ILIM2

VCC

OUT

GND

GATESENSEVEE

VEE

LM5067

CIN

RIN

VSYS

LM5067

SNVS532C –OCTOBER 2007–REVISED MARCH 2013

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• RLis the load resistance and VSYS is the absolute value of the system input voltage (5)

The Fault Timeout Period must be set longer than tON to prevent a fault shutdown before the turn-on

sequence is complete.

Figure 12. Load Draws Current During Turn-On

B) Turn-on with power limit and current limit: The power dissipation limit in Q1 (PFET(LIM)) is defined by the

resistor at the PWR pin, and the current sense resistor RS. See POWER LIMIT THRESHOLD. If the current limit

threshold (ILIM) is higher than the current defined by the power limit threshold at maximum VDS (PFET(LIM)/VSYS)

the circuit operates initially in power limit mode when the VDS of Q1 is high, and then transitions to current limit

mode as the current increases to ILIM as VDS decreases. See Figure 13b. Assuming the load (RL) is not

connected during turn-on, the time for the output voltage to reach its final value is approximately equal to:

(6)

For example, if VSYS = -48V, CL= 1000 µF, ILIM = 1A, and PFET(LIM) = 20W, tON calculates to ≊68 ms, and the

initial current level (IP) is approximately 0.42A. The Fault Timeout Period must be set longer than tON.

Figure 13. MOSFET Power Up Waveforms

MOSFET SELECTION

It is recommended that the external MOSFET (Q1) selection be based on the following criteria:

• The BVDSS rating should be greater than the maximum system voltage (VSYS), plus ringing and transients

which can occur at VSYS when the circuit card, or adjacent cards, are inserted or removed.

• The maximum continuous current rating should be based on the current limit threshold (50 mV/RS), not the

maximum load current, since the circuit can operate near the current limit threshold continuously.

• The Pulsed Drain Current spec (IDM) must be greater than the current threshold for the circuit breaker function

(100 mV/RS).

Product Folder Links: LM5067

tRESTART = CT x 7 x 2.75V

2.5 PA7 x 2.75V

85 PA3.7V

2.5 PA

CT = tFAULT x 85 PA

4V = tFAULT x 2.13 x 10-5

CT = t1 x 6 PA

4V = t1 x 1.5 x 10-6

LM5067

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SNVS532C –OCTOBER 2007–REVISED MARCH 2013

• The SOA (Safe Operating Area) chart of the device, and the thermal properties, should be used to determine

the maximum power dissipation threshold set by the RPWR resistor. The programmed maximum power

dissipation should have a reasonable margin from the maximum power defined by the FET's SOA chart if the

LM5067-2 is used since the FET will be repeatedly stressed during fault restart cycles. The FET manufacturer

should be consulted for guidelines.

• RDS(on) should be sufficiently low that the power dissipation at maximum load current (IL(max)2x RDS(on)) does

not raise its junction temperature above the manufacturer’s recommendation.

If the device chosen for Q1 has a maximum VGS rating less than 13V, an external zener diode must be added

from its gate to source, with the zener voltage less than the maximum VGS rating. The zener diode’s forward

current rating must be at least 110 mA to conduct the GATE pull-down current during startup and in the circuit

breaker mode.

TIMER CAPACITOR, CT

The TIMER pin capacitor (CT) sets the timing for the insertion time delay, fault timeout period, and restart timing

of the LM5067-2.

A) Insertion Delay - Upon applying the system voltage (VSYS) to the circuit, the external MOSFET (Q1) is held

off during the insertion time (t1 in Figure 6) to allow ringing and transients at VSYS to settle. Since each

backplane’s response to a circuit card plug-in is unique, the worst case settling time must be determined for each

application. The insertion time starts when the operating voltage (VCC-VEE) reaches the PORIT threshold, at

which time the internal 6 µA current source charges CTfrom 0V to 4.0V. The required capacitor value is

calculated from:

where

• t1 is the desired insertion delay (7)

For example, if the desired insertion delay is 250 ms, CTcalculates to 0.38 µF. At the end of the insertion delay,

CTis quickly discharged by a 1.5 mA current sink.

B) Fault Timeout Period - During turn-on of the output voltage, or upon detection of a fault condition where the

current limit and/or power limit circuits regulate the current through Q1, CTis charged by the fault timer current

source (85 µA). The Fault Timeout Period is the time required for the TIMER pin voltage to reach 4.0V above

VEE, at which time Q1 is switched off. The required capacitor value for the desired Fault Timeout Period tFAULT is

calculated from:

(8)

For example, if the desired Fault Timeout Period is 16 ms, CTcalculates to 0.34 µF. After a fault timeout, if the

LM5067-1 is in use, CTmust be allowed to discharge to <0.3V by the 2.5 µA current sink, after which a power up

sequence can be initiated by external circuitry. See Fault Timer and Restart and Figure 8. If the LM5067-2 is in

use, after the Fault Timeout Period expires a restart sequence begins as described below (Restart Timing).

Since the LM5067 normally operates in power limit and/or current limit during a power up sequence, the Fault

Timeout Period MUST be longer than the time required for the output voltage to reach its final value. See TURN-

ON TIME.

C) Restart Timing If the LM5067-2 is in use, after the Fault Timeout Period described above, CTis discharged

by the 2.5 µA current sink to 1.25V. The TIMER pin then cycles through seven additional charge/discharge

cycles between 1.25V and 4.0V as shown in Figure 9. The restart time ends when the TIMER pin voltage

reaches 0.3V during the final high-to-low ramp. The restart time, after the Fault Timeout Period, is equal to:

= CTx 9.4 x 106(9)

Product Folder Links: LM5067

VOVL = [(R1 + R2) x ((2.5V) - 22 PA)] + 2.5V

R1 = VUVH - VUVL

22 PA=VUV(HYS)

22 PA

R3 = 2.5V x R1 x VUVL

VOVH x (VUVL - 2.5V)

R2 = 2.5V x R1

VUVL - 2.5V - R3

OVLO

VEE

TIMER AND GATE

LOGIC CONTROL

GND

VEE

To Load

Vee

LM5067

22 PA

CIN

RIN

VSYS

UVLO/EN

22 PA

Vee

2.50V

VCC

LM5067

SNVS532C –OCTOBER 2007–REVISED MARCH 2013

www.ti.com

For example, if CT= 0.33 µF, tRESTART = 3.1 seconds. At the end of the restart time, Q1 is switched on. If the fault

is still present, the fault timeout and restart sequence repeats. The on-time duty cycle of Q1 is approximately

0.5% in this mode.

UVLO, OVLO

By programming the UVLO and OVLO thresholds the LM5067 enables the series pass device (Q1) when the

input supply voltage (VSYS) is within the desired operational range. If VSYS is below the UVLO threshold, or above

the OVLO threshold, Q1 is switched off, denying power to the load. Hysteresis is provided for each threshold.

NOTE

All voltages are with respect to Vee in the discussions below. Use absolute values in the

equations.

Option A: The configuration shown in Figure 14 requires three resistors (R1-R3) to set the thresholds.

Figure 14. UVLO and OVLO Thresholds Set By R1-R3

The procedure to calculate the resistor values is as follows:

• Determine the upper UVLO threshold (VUVH) to enable Q1, and the lower UVLO threshold (VUVL) to disable

Q1.

• Determine the upper OVLO threshold (VOVH) to disable Q1.

• The lower OVLO threshold (VOVL), to enable Q1, cannot be chosen in advance in this case, but is determined

after the values for R1-R3 are determined. If VOVL must be accurately defined in addition to the other three

thresholds, see Option B below.

The resistors are calculated as follows:

(10)

The lower OVLO threshold is calculated from:

(11)

Product Folder Links: LM5067

VUVH = 2.5V + [R1 x (22 PA + (R2 + R3)

2.5V )]

VUVL = 2.5V x (R1 + R2 + R3)

R2 + R3

VOVH = 2.5V x (R1 + R2 + R3)

VOVL = [(R1 + R2) x (2.5V) - 22 PA)] + 2.5V

VOV(HYS) = (R1 + R2) x 22 PA

VUV(HYS) = R1 x 22 PA

R1 = 36V ± 32V

22 PA=4V

22 PA= 182 k:

R3 = 2.5V x 182 k: x 32V

60V x (32V - 2.5V) = 8.23 k:

R2 = 2.5V x 182 k:

(32V - 2.5V) - 8.23 k: = 7.19 k:

LM5067

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SNVS532C –OCTOBER 2007–REVISED MARCH 2013

As an example, assume the application requires the following thresholds: VUVH = -36V, VUVL = -32V, VOVH = -

60V.

(12)

The lower OVLO threshold calculates to -55.8V, and the OVLO hysteresis is 4.2V. Note that the OVLO

hysteresis is always slightly greater than the UVLO hysteresis in this configuration.

When the R1-R3 resistor values are known, the threshold voltages and hysteresis are calculated from the

following:

(13)

NOTE

Ensure the voltages at the UVLO and OVLO pins do not exceed the Absolute Maximum

ratings for those pins when the system voltage is at maximum.

Option B: If all four thresholds must be accurately defined, the configuration in Figure 15 can be used.

Product Folder Links: LM5067

R4 = (VOVH - 2.5V)

2.5V x R3

R3 = VOVH - VOVL

22 PA=VOV(HYS)

22 PA

R2 = (VUVL - 2.5V)

2.5V x R1

R1 = VUVH - VUVL

22 PA=VUV(HYS)

22 PA

VCC

OVLO

VEE

TIMER AND GATE

LOGIC CONTROL

GND

VEE

To Load

Vee

LM5067

22 PA

CIN

RIN

VSYS

UVLO/EN

2.50V

22 PA

LM5067

SNVS532C –OCTOBER 2007–REVISED MARCH 2013

www.ti.com

Figure 15. Programming the Four Thresholds

The four resistor values are calculated as follows:

• Determine the upper UVLO threshold (VUVH) to enable Q1, and the lower UVLO threshold (VUVL) to disable

Q1.

(14)

• Determine the upper OVLO threshold (VOVH) to disable Q1, and the lower OVLO threshold (VOVL) to enable

Q1.

(15)

As an example, assume the application requires the following thresholds: VUVH = -22V, VUVL = -17V, VOVH = -

60V, and VOVL = -58V. Therefore VUV(HYS) = 5V, and VOV(HYS) = 2V. The resistor values are:

R1 = 227 kΩ, R2 = 39.1 kΩ

R3 = 90.9 kΩ, R4 = 3.95 kΩ

Where the R1-R4 resistor values are known, the threshold voltages and hysteresis are calculated from the

following:

Product Folder Links: LM5067

50k

OVLO

VEE

TIMER AND GATE

LOGIC CONTROL

GND

VEE

To Load

Vee

LM5067

22 PA

CIN

RIN

VSYS

UVLO/EN 2.5V

2.5V

22 PA

VCC

VUVH = 2.5V + [R1 x (2.5V + 22 PA)]

VUVL = 2.5V x (R1 + R2)

VOVH = 2.5V x (R3 + R4)

VOVL = 2.5V + [R3 x (2.5V - 22 PA)]

VOV(HYS) = R3 x 22 PA

VUV(HYS) = R1 x 22 PA

LM5067

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SNVS532C –OCTOBER 2007–REVISED MARCH 2013

(16)

NOTE

Ensure the voltages at the UVLO and OVLO pins do not exceed the Absolute Maximum

ratings for those pins when the system voltage is at maximum.

Option C: The minimum UVLO level is obtained by connecting the UVLO pin to VCC as shown in Figure 16. Q1

is switched on when the operating voltage reaches the POREN threshold (≊8.4V). The OVLO thresholds are set

by R3 and R4 using the procedure in Option B.

NOTE

Ensure the voltage at the OVLO pin does not exceed the Absolute Maximum ratings for

that pin when the system voltage is at maximum.

Figure 16. UVLO = POREN

Option D: The OVLO function can be disabled by connecting the OVLO pin to VEE. The UVLO thresholds are

set as described in Option B or Option C.

Product Folder Links: LM5067

VPGD

Power

Good

LM5067

VEE

CIN

VSYS

RIN VEE

PGD

GND

RPG

VCC

Shutdown

Control

VCC

OVLO

VEE

System Gnd VEE

SENSE

VSYS

CIN

RIN

UVLO/EN

LM5067

Shutdown

Control

VCC

OVLO

VEE

System Gnd VEE

SENSE

VSYS

CIN

RIN

100k

UVLO/EN

LM5067

SNVS532C –OCTOBER 2007–REVISED MARCH 2013

www.ti.com

SHUTDOWN / ENABLE CONTROL

Figure 17 shows how to use the UVLO/EN pin for remote shutdown and enable control. Taking the UVLO/EN pin

below its 2.5V threshold (with respect to VEE) shuts off the load current. Upon releasing the UVLO/EN pin the

LM5067 switches on the load current with in-rush current and power limiting. In Figure 18 the OVLO pin is used

for remote shutdown and enable control. When the external transistor is off, the OVLO pin is above its 2.5V

threshold (with respect to VEE) and the load current is shut off. Turning on the external transistor allows the

LM5067 to switch on the load current with in-rush current and power limiting.

Figure 17. a) Shutdown/Enable Using the UVLO/EN Figure 18. b) Shutdown/Enable Using the OVLO

Pin Pin

POWER GOOD PIN

During initial power up, the Power Good pin (PGD) is high until the operating voltage (VCC – VEE) increases

above ≊2V. PGD then switches low, remaining low as the system voltage and the operating voltage increase.

After Q1 is switched on, when the voltage at the OUT pin is within 1.23V of the SENSE pin (Q1’s VDS <1.23V),

PGD switches high indicating the output voltage is at, or nearly at, its final value. Any of the following situations

will cause PGD to switch low within ≊10 µs:

• The VDS of Q1 increases above 2.5V.

• The system input voltage decreases below the UVLO level.

• The system input voltage increase above the OVLO level.

• The TIMER pin increases to 4V due to a fault condition.

A pull-up resistor is required at PGD as shown in Figure 19. The pull-up voltage (VPGD) can be as high as 80V

above VEE, with transient capability to 100V, and can be higher or lower than the system ground.

Figure 19. Power Good Output

If a delay is required at PGD, suggested circuits are shown in Figure 20.InFigure 20a, capacitor CPG adds delay

to the rising edge, but not to the falling edge. In Figure 20b, the rising edge is delayed by RPG1 + RPG2 and CPG,

while the falling edge is delayed a lesser amount by RPG2 and CPG. Adding a diode across RPG2.Figure 20c

allows for equal delays at the two edges, or a short delay at the rising edge and a long delay at the falling edge.

Product Folder Links: LM5067

VEE

PGD

Power

Good

LM5067

PGD

Power

Good

LM5067

PGD

Power

Good

LM5067

RPG2

a) Delay Rising Edge Only b) Long delay at rising edge,

Short delay at falling edge c) Short Delay at Rising Edge and Long

VEE VEE

CPG CPG

RPG1

RPG2

VSYS

CPG

VPGD

RPG

VSYS

Delay at Falling Edge, or Equal Delays

VSYS

VPGD

RPG1

LM5067

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SNVS532C –OCTOBER 2007–REVISED MARCH 2013

Figure 20. Adding Delay to the Power Good Output Pin

Design-in Procedure

The recommended design-in procedure for the LM5067 is as follows:

• Determine the minimum and maximum system voltages (VEE). Select the input resistor (RIN) to provide at

least 2 mA into the VCC pin at the minimum system voltage.The resistor’s power rating must be suitable for

its power dissipation at maximum system voltage ((VSYS – 13V)2/RIN).

• Determine the current limit threshold (ILIM). This threshold must be higher than the normal maximum load

current, allowing for tolerances in the current sense resistor value and the LM5067 Current Limit threshold

voltage. Use equation 1 to determine the value for RS.

• Determine the maximum allowable power dissipation for the series pass FET (Q1), using the device’s SOA

information. Use equation 2 to determine the value for RPWR.

• Determine the value for the timing capacitor at the TIMER pin (CT) using equation 3. The fault timeout

period (tFAULT) must be longer than the circuit’s turn-on-time. The turn-on time can be estimated using

the equations in the Turn-on Time section of this data sheet, but should be verified experimentally. Allow for

tolerances in the values of the external capacitors, sense resistor, and the LM5067 Electrical Characteristics

for the TIMER pin, current limit and power limt. Review the resulting insertion time, and the restart timing if

the LM5067-2 is used.

• Choose option A, B, C, or D from the UVLO, OVLO section of the Application Information for setting the

UVLO and OVLO thresholds and hysteresis. Use the procedure in the appropriate option to determine the

resistor values at the UVLO and OVLO pins.

• Choose the appropriate voltage, and pull-up resistor, for the Power Good output.

PC Board Guidelines

The following guidelines should be followed when designing the PC board for the LM5067:

• Place the LM5067 close to the board’s input connector to minimize trace inductance from the connector to the

FET.

• Place RIN and CIN close to the VCC and VEE pins to keep transients below the Absolute Maximum rating of

the LM5067. Transients of several volts can easily occur when the load current is shut off.

• The sense resistor (RS) should be close to the LM5067, and connected to it using the Kelvin techniques

shown in Figure 10.

• The high current path from the board’s input to the load, and the return path (via Q1), should be parallel and

close to each other wherever possible to minimize loop inductance.

• The VEE connection for the various components around the LM5067 should be connected directly to each

other, and to the LM5067’s VEE pin, and then connected to the system VEE at one point. Do not connect the

various components to each other through the high current VEE track.

• Provide adequate heat sinking for the series pass device (Q1) to help reduce thermal stresses during turn-on

and turn-off.

• The board’s edge connector can be designed to shut off the LM5067 as the board is removed, before the

supply voltage is disconnected from the LM5067. In Figure 21 the voltage at the UVLO/EN pin goes to VEE

before VSYS is removed from the LM5067 due to the shorter edge connector pin. When the board is inserted

into the edge connector, the system voltage is applied to the LM5067’s VEE and VCC pins before voltage is

applied to the UVLO/EN pin.

Product Folder Links: LM5067

GND

CARD EDGE

CONNECTOR

SENSE

VCC

UVLO

OVLO

VEE

GATE

OUT

PGD

PWR TIMER

RIN LM5067

CIN To

Load

PLUG-IN CARD

VSYS

LM5067

SNVS532C –OCTOBER 2007–REVISED MARCH 2013

www.ti.com

• If power dissipation within the LM5067 is high, an exposed copper pad should be provided beneath the

package, and that pad should be connected to exposed copper on the board’s other side with as many vias

as possible. See Thermal Considerations.

Figure 21. Suggested Board Connector Design

Thermal Considerations

The LM5067 should be operated so that its junction temperature does not exceed 125°C. The junction

temperature is equal to:

TJ= TA+ (RθJA x PD)

where

• TAis the ambient temperature

• RθJA is the thermal resistance of the LM5067 (17)

PDis the power dissipated within the LM5067, calculated from:

PD= 13V x ICC

where

• ICC is the current into the VCC pin (the current through the RIN resistor). (18)

Values for RθJA and RθJC are in Electrical Characteristics.

System Considerations

1. Continued proper operation of the LM5067 hot swap circuit requires capacitance be present on the supply

side of the connector into which the hot swap circuit is plugged in, as depicted in Figure 5. The capacitor in

the “Live Backplane” section is necessary to absorb the transient generated whenever the hot swap circuit

shuts off the load current. If the capacitance is not present, inductance in the supply lines will generate a

voltage transient at shut-off which can exceed the absolute maximum rating of the LM5067, resulting in its

destruction.

2. If the load powered via the LM5067 hot swap circuit has inductive characteristics, a diode is required across

the LM5067’s output to provide a recirculating path for the load’s current. Adding the diode prevents possible

damage to the LM5067 as the OUT pin will be taken above ground by the inductive load at shutoff. See

Figure 22.

Product Folder Links: LM5067

Inductive

Load

VCC

GND

BACKPLANE

PGD

OUT

LIVE

Q1 VOUT

GATESENSEVEE

VSYS

RIN

LM5067

-48V

PLUG-IN BOARD

CIN

LM5067

www.ti.com

SNVS532C –OCTOBER 2007–REVISED MARCH 2013

Figure 22. Output Diode Required for Inductive Loads

Product Folder Links: LM5067

LM5067

SNVS532C –OCTOBER 2007–REVISED MARCH 2013

www.ti.com

REVISION HISTORY

Changes from Revision B (March 2013) to Revision C Page

• Changed layout of National Data Sheet to TI format .......................................................................................................... 27

Product Folder Links: LM5067

PACKAGE OPTION ADDENDUM

www.ti.com 15-Apr-2017

Addendum-Page 1

PACKAGING INFORMATION

Orderable Device Status

(1)

Package Type Package

Drawing Pins Package

Qty Eco Plan

(2)

Lead/Ball Finish

(6)

MSL Peak Temp

(3)

Op Temp (°C) Device Marking

(4/5)

Samples

LM5067MM-1/NOPB ACTIVE VSSOP DGS 10 1000 Green (RoHS

& no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 SRUB

LM5067MM-2 NRND VSSOP DGS 10 1000 TBD Call TI Call TI -40 to 125 SRVB

LM5067MM-2/NOPB ACTIVE VSSOP DGS 10 1000 Green (RoHS

& no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 SRVB

LM5067MMX-2/NOPB ACTIVE VSSOP DGS 10 3500 Green (RoHS

& no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 SRVB

LM5067MW-1/NOPB ACTIVE SOIC NPA 14 50 Green (RoHS

& no Sb/Br) CU SN Level-3-260C-168 HR LM5067

MW-1

LM5067MWX-1/NOPB ACTIVE SOIC NPA 14 1000 Green (RoHS

& no Sb/Br) CU SN Level-3-260C-168 HR -40 to 125 LM5067

MW-1

(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) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability

information and additional product content details.

TBD: The Pb-Free/Green conversion plan has not been defined.

Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that

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

Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between

the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above.

Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight

in homogeneous material)

(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.

PACKAGE OPTION ADDENDUM

www.ti.com 15-Apr-2017

Addendum-Page 2

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

LM5067MM-1/NOPB VSSOP DGS 10 1000 178.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1

LM5067MM-2 VSSOP DGS 10 1000 178.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1

LM5067MM-2/NOPB VSSOP DGS 10 1000 178.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1

LM5067MMX-2/NOPB VSSOP DGS 10 3500 330.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1

LM5067MWX-1/NOPB SOIC NPA 14 1000 330.0 16.4 10.9 9.5 3.2 12.0 16.0 Q1

PACKAGE MATERIALS INFORMATION

www.ti.com 18-Aug-2014

Pack Materials-Page 1

*All dimensions are nominal

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

LM5067MM-1/NOPB VSSOP DGS 10 1000 210.0 185.0 35.0

LM5067MM-2 VSSOP DGS 10 1000 210.0 185.0 35.0

LM5067MM-2/NOPB VSSOP DGS 10 1000 210.0 185.0 35.0

LM5067MMX-2/NOPB VSSOP DGS 10 3500 367.0 367.0 35.0

LM5067MWX-1/NOPB SOIC NPA 14 1000 367.0 367.0 38.0

PACKAGE MATERIALS INFORMATION

www.ti.com 18-Aug-2014

Pack Materials-Page 2

MECHANICAL DATA

NPA0014B

www.ti.com

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