LM2724A

High Speed 3A Synchronous MOSFET Driver

General Description

The LM2724A is a dual N-channel MOSFET driver which

can drive both the top and bottom MOSFETs in a push-pull

structure simultaneously. The LM2724A takes a logic input

and splits it into two complimentary signals with a typical

20ns dead time in between. The built-in cross-conduction

protection circuitry prevents the top and bottom MOSFETs

from turning on simultaneously. With a bias voltage of 5V, the

peak sourcing and sinking current for each driver of the

LM2724A is about 3A. Input UVLO (Under-Voltage-Lock-

Out) ensures that all the driver outputs stay low until the

supply rail exceeds the power-on threshold during system

power on, or after the supply rail drops below power-on

threshold by a specified hysteresis during system power

down. The cross-conduction protection circuitry detects both

driver outputs and will not turn on a driver until the other

driver output is low. The top gate voltage needed by the top

MOSFET is obtained through an external boot-strap struc-

ture. When not switching, the LM2724A only draws up to

195µA from the 5V rail. The synchronization operation of the

bottom MOSFET can be disabled by pulling the SYNC pin to

ground.

Features

n

Shoot-through protection

n

Input Under-Voltage-Lock-Out

n

3A peak driving current

n

195µA quiescent current

n

28V input voltage in buck configuration

n

SO-8 and LLP packages

Applications

n

High Current DC/DC Power Supplies

n

High Input Voltage Switching Regulators

n

Fast Transient Microprocessors

n

Notebook Computers

Typical Application

20073501

June 2003

© 2003 National Semiconductor Corporation

DS200735

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