LM2725/LM2726

High Speed Synchronous MOSFET Drivers

General Description

The LM2725/LM2726 is a family of dual MOSFET drivers

that can drive both the top MOSFET and bottom MOSFET in

a push-pull structure simultaneously. It takes a logic level

PWM input and splits it into two complimentary signals with

a

typical

20ns

dead

time

in

between. The

built-in

shoot-through protection circuitry prevents the top and bot-

tom FETs from turning on simultaneously. With a bias volt-

age of 5V, the peak sourcing and sinking current for each

driver of the LM2725 is about 1.2A and that of the LM2726 is

about 3A. In an SO-8 package, each driver is able to handle

50mA

average

current.

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 de-

tects both the driver outputs and will not turn on a driver until

the other driver output is low. The top gate bias voltage

needed by the top MOSFET can be obtained through an

external bootstrap structure. Minimum pulse width is as low

as 55ns.

Features

n

High peak output current

n

Adaptive shoot-through protection

n

36V SW pin absolute maximum voltage

n

Input Under-Voltage-Lock-Out

n

Typical 20ns internal delay

n

Plastic 8-pin SO package

Applications

n

High Current DC/DC Power Supplies

n

High Input Voltage Switching Regulators

n

Microprocessors

Typical Application

Connection Diagram

DS200072-1

8-Lead Small Outline Package

DS200072-2

Top View

November 2000

© 2000 National Semiconductor Corporation

DS200072

www.national.com