LT4356MP-1/LT4356MP-2

1

4356mp12f

APPLICATIONS

FEATURES

DESCRIPTION

Surge Stopper

transients. It regulates the output during an overvoltage

event, such as load dump in automobiles, by controlling

the gate of an external N-channel MOSFET. The output

is limited to a safe value thereby allowing the loads to

continue functioning. The LT4356MP also monitors the

against overcurrent faults. An internal amplifier limits the

current sense voltage to 50mV. In either fault condition, a

timer is started inversely proportional to MOSFET stress.

If the timer expires, the FLT pin pulls low to warn of an

impending power-down. If the condition persists, the

MOSFET is turned off. After a cooldown period, the GATE

pin pulls up turning on the MOSFET again.

The spare amplifier may be used as a voltage detection

comparator or as a linear regulator controller driving an

external PNP pass transistor.

Back-to-back FETs can be used in lieu of a Schottky diode

for reverse input protection, reducing voltage drop and

power loss. A shutdown pin reduces the quiescent current

to less than 7μA during shutdown for the LT4356-1 and

60μA for the LT4356-2 while keeping the reference and

auxiliary amplifier functioning.

Linear Regulator Controller

4A, 12V Overvoltage Output Regulator

Overvoltage Protector Regulates Output at

27V During Transient

L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.

All other trademarks are the property of their respective owners.

0.1μF

10Ω

10mΩ

IRLR2908

12V

4356mp12 TA01

LT4356S

GND

TMR

OUT

GATE

SNS

SHDN

FAULT

EN

FLT

UNDERVOLTAGE

FB

DC-DC

CONVERTER

GND

SHDN

4.99k

383k

100k

102k

100ms/DIV

4356mp12 TA01b

20V/DIV

20V/DIV

80V INPUT SURGE

27V ADJUSTABLE CLAMP

12V

12V

TYPICAL APPLICATION