LTC4444

1

4444f

TYPICAL APPLICATION

FEATURES

APPLICATIONS

DESCRIPTION

High Voltage Synchronous

N-Channel MOSFET Driver

The LTC

that drives two N-channel MOSFETs in a synchronous

DC/DC converter with supply voltages up to 100V. The

powerful driver capability reduces switching losses in

MOSFETs with high gate capacitance. The LTC4444’s

pull-up for the top gate driver has a peak output current

of 2.5A and its pull-down has an output impedance of

1.2

Ω. The pull-up for the bottom gate driver has a peak

output current of 3A and the pull-down has an output

impedance of 0.55

Ω.

The LTC4444 is configured for two supply-independent

inputs. The high side input logic signal is internally

level-shifted to the bootstrapped supply, which may

function at up to 114V above ground.

The LTC4444 contains undervoltage lockout circuits that

disable the external MOSFETs when activated. The LTC4444

also contains adaptive shoot-through protection to prevent

both MOSFETs from conducting simultaneously.

The LTC4444 is available in the thermally enhanced 8-lead

MSOP package.

Ω TG Driver Pull-Down

Ω BG Driver Pull-Down

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

All other trademarks are the property of their respective owners.

Protected by U.S. Patents, including 6677210.

High Input Voltage Buck Converter

TG

BOOST

100V

(ABS MAX)

GND

TS

TINP

LTC4444

BG

PWM2

(FROM CONTROLLER IC)

PWM1

(FROM CONTROLLER IC)

7.2V TO 13.5V

BINP

4444 TA01a

LTC4444 Driving a 1000pF Capacitive Load

BINP

5V/DIV

BG

10V/DIV

TINP

5V/DIV

TG-TS

10V/DIV

20ns/DIV

4444 TA01b