LT1374-SYNC

Features:

Constant 500kHz Switching Frequency
Easily Synchronizable
Uses All Surface Mount Components
Inductor Size Reduced to 1.8H
Saturating Switch Design: 0.07
Effective Supply Current: 2.5mA
Cycle-by-Cycle Current Limiting


Application

Portable Computers
Battery-Powered Systems
Battery Charger
Distributed Power


Pinout




Specifications

Input Voltage ........................................................... 25V
BOOST Pin Above Input Voltage .............................. 15V
BIAS Pin Voltage ...................................................... 7V
FB Pin Voltage (Adjustable Part) .............................. 3.5V
FB Pin Current (Adjustable Part) .............................. 1mA
SYNC Pin Voltage ..................................................... 7V
Operating Junction Temperature Range
    LT1374CS8-SYNC ................................................. 0°C to 125° C
    LT1374IS8-SYNC .................................................. 40°C to 125°C
Storage Temperature Range .................................... 65°C to 150°C
Lead Temperature (Soldering, 10 sec)...................... 300°C


Description

The LT^®1374-SYNC is a 500kHz monolithic buck mode switching regulator. A 4.5A switch is included on the die along with all the necessary oscillator, control and logic circuitry. High switching frequency allows a considerable reduction in the size of external components. The topology is current mode for fast transient response and good loop stability. Both fixed output voltage and adjustable parts are available.

A special high speed bipolar process and new design techniques of LT1374-SYNC achieve high efficiency at high switching frequency. Efficiency is maintained over a wide output current range by using the output to bias the circuitry and by utilizing a supply boost capacitor to saturate the power switch.

The LT1374-SYNC fits into a fused lead SO-8 package. Full cycle-by-cycle short-circuit protection and thermal shutdown are provided. Standard surface mount external parts are used, including the inductor and capacitors. Synchronization allows an external logic level signal to increase the internal oscillator from 580kHz to 1MHz.