POWER MANAGEMENT

1

www.semtech.com

SC1214

Two-Phase, Synchronous MOSFET Driver

Features

Applications

May 9, 2005

driver designed to drive high-side and low-side MOSFETs

in two synchronous Buck converters. The driver com-

bined with Combi-Sense PWM controllers, such as

Semtech SC2643VX or SC2643, provides a cost effec-

tive two-phase voltage regulator for advanced micro-

processors

current for peak current mode control of voltage regula-

tor without using sensing resistor. It provides the follow-

ing advantages:

- No costly precision sensing resistor

- Lossless current sensing

- High level noise free signal

- Fast response

- Suitable for wide range of duty cycle

The detailed explanation of the technique can be found

in the Applications Information section.

A 30ns max propagation delay from input transition to

the gate of the power FET’s guarantees operation at high

switching frequencies. Internal overlap protection circuit

prevents shoot-through from Vin to PGND in the main

and synchronous MOSFETs. The adaptive overlap pro-

tection circuit ensures the bottom FET does not turn on

until the top FET source has reached 1V, to prevent cross-

conduction.

High current drive capability allows fast switching, thus

reducing switching losses at high (up to 1.5MHz) frequen-

cies without causing thermal stress on the driver.

Under-voltage-lockout and over-temperature shutdown

features are included for proper and safe operation.

Timed latches and improved robustness are built into

the housekeeping functions such as the Under Voltage

Lockout and adaptive Shoot-through protection circuitry

to prevent false triggering and to assure safe operation.

The SC1214 is offered in a TSSOP-20 package.

shoot-through protection

load)

of small inductors and low cost ceramic capacitors

supplies

Description