LTC4231

1

Rev. B

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TYPICAL APPLICATION

FEATURES

DESCRIPTION

Micropower Hot Swap

Controller

The LTC®4231 is a micropower Hot Swap controller that

allows safe circuit board insertion and removal from a live

power supply. An internal high side switch driver controls

the gate of an external N-channel MOSFET. Back-to-back

MOSFETs can be used for reverse supply protection down

to –40V.

The LTC4231 provides a debounce delay and allows the

GATE to be ramped up at an adjustable rate. After start-

up, the LTC4231's quiescent current drops to 4µA during

normal operation with output active. UVL, UVH, OV and

GNDSW monitor overvoltage and undervoltage periodi-

cally, keeping total quiescent current low. Pulling SHDN

low shuts down the LTC4231 and quiescent current drops

to 0.3µA.

During an overcurrent fault, the LTC4231 actively limits

current while running an adjustable timer. The LTC4231-1

remains off after a current fault while the LTC4231-2 auto-

matically reapplies power after a cool-down period.

Battery Hot Swap with Reverse Protection

APPLICATIONS

n

Enables Safe Board Insertion and Removal from a

Power Supply

n

4µA Supply Current

n

0.3µA Shutdown Current

n

Wide Operating Voltage Range: 2.7V to 36V

n

Reverse Supply Protection to –40V

n

Adjustable Analog Current Limit with Circuit Breaker

n

Automatic Retry or Latchoff on Current Fault

n

Overvoltage and Undervoltage Monitoring

n

Controls Single or Back-to-Back N-Channel MOSFETs

n

12-Lead MSOP and 3mm × 3mm QFN Packages

n

AEC-Q100 Qualified for Automotive Applications

n

Battery Powered Equipment

n

Solar Powered Systems

n

Portable Instruments

n

Automotive Battery Protection

n

Energy Harvesting

SENSE

GATE

IN

UVL

UVH

OV

GNDSW

SOURCE

STATUS

SHDN

TIMER

LTC4231

Si7164DP

SMAJ24CA

22.5m

Si5410DU

GND

20k

220µF

24V

2A

1020k

1.65k

24V

4.22k

32.4k

180nF

4231 TA01a

GATE

20V/DIV

IN

20V/DIV

SOURCE

20V/DIV

5A/DIV

10ms/DIV

4231 TA01b

CONTACT

BOUNCE

Power-Up Waveforms

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