LT4356-1

1

43561fd

APPLICATIONS

FEATURES

DESCRIPTION

Overvoltage Protection

Regulator and Inrush Limiter

voltage 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 LT4356-1 also monitors

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.

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.

Linear Regulator Controller

× 3mm) 12-Pin DFN or 10-Pin

MSOP Packages

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

43561 TA01

LT4356DE-1

GND

TMR

OUT

GATE

SNS

SHDN

FAULT

EN

FLT

UNDERVOLTAGE

FB

DC-DC

CONVERTER

GND

SHDN

4.99k

383k

100k

102k

100ms/DIV

43561 TA01b

20V/DIV

20V/DIV

80V INPUT SURGE

27V CLAMP

12V

12V

TYPICAL APPLICATION