POWER MANAGEMENT

January 4, 2008



Simple PWM Boost Controller

with Input Disconnect FET Drive

SC2604

www.semtech.com

Typical Application Circuit

Features

Input Voltage Range: 4.5V to 3.5V

% Voltage Reference Accuracy

Up to 95% Efficiency

Input Disconnect FET Drive

In-rush Current Control

Internal Compensation

Programmable Current Limit

Programmable Soft Start

800mA Typical PWM Gate Drive

400kHz Switching Frequency

Under Voltage Lockout

<200uA Shutdown Current

MSOP-8 Package, Fully WEEE and RoHS Compliant

Applications

Portable Devices

Flat Panel TV

TV Set Top Box

Auxiliary Supplies

Peripheral Card Supplies

Industrial Power Supply

High Density DC/DC Conversion

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Description

The SC2604 is a versatile, low-cost, voltage-mode PWM

controller designed for boost DC/DC power supply

applications. It features input disconnect FET driver

allowing power source and load separation at shutdown

mode, which eliminates possible leakage current from

source to load. Also, it prevents catastrophic failure when

output is shorted during operation.

The SC2604 also includes temperature compensated

voltage reference, internal ramp, current limit comparator,

internally compensated error amplifier, and floating driver

with charge pump. Programmable soft start controls

in-rush current and reduces output voltage overshoot.

Hiccup mode over-current protection allows system auto-

retry and ease of trouble shooting.

Internally compensated feedback loop makes power

supply design simple, and eliminates the need for external

compensation network.

The SC2604 is available in MSOP-8 package with rated

Figure 1. 12V to 25V/1A Boost Converter with Over Current Protection