LTC4443/LTC4443-1

1

4443fa

× 3mm DFN Package

TYPICAL APPLICATION

FEATURES

APPLICATIONS

DESCRIPTION

High Speed Synchronous

N-Channel MOSFET Drivers

The LTC

bootstrap Schottky diode designed to drive two N-channel

MOSFETsinasynchronousbuckDC/DCconvertertopology.

The powerful driver capability reduces switching losses

in MOSFETs with high gate capacitance.

The LTC4443 features a separate supply for the input logic

to match the signal swing of the controller IC. If the input

signal is not being driven, the LTC4443 activates a shutdown

mode that turns off both external MOSFETs. The input

logic signal is internally level-shifted to the bootstrapped

supply, which may function at up to 42V above ground.

The Schottky diode required for the bootstrapped supply

is integrated to simplify layout and reduce parts count.

The LTC4443 contains undervoltage lockout circuits on

both the driver and logic supplies that turn off the external

MOSFETs when an undervoltage condition is present.

The LTC4443 and LTC4443-1 have different undervoltage

lockout thresholds to accommodate a wide variety of ap-

plications. An adaptive shoot-through protection feature is

also built-in to prevent power loss resulting from MOSFET

cross-conduction current.

The LTC4443/LTC4443-1 are available in a tiny 3mm

×

3mm DFN package.

Synchronous Buck Converter Driver

LTC4443 Driving 3000pF Capacitive Loads

TG

BOOST

32V

GND

TS

BG

PWM

6V

IN

4443 TA01a

INPUT (IN)

5V/DIV

BOTTOM

GATE (BG)

5V/DIV

TOP GATE

(TG-TS)

5V/DIV

10ns/DIV

4443 TA01b

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

All other trademarks are the property of their respective owners.