LT4430

Features:

600mV Reference (1.25% Over Temperature)
Wide Input Supply Range: 3V to 20V
Overshoot Control Function Prevents Output Overshoot on Startup and Short-Circuit Recovery
High Bandwidth Error Amplifi er Permits Simple Loop Frequency Compensation
Ground-Referenced OptoCoupler Drive
10mA OptoCoupler Drive with Current Limiting
Low Profi le (1mm) ThinSOTTM Package


Application

48V Input Isolated DC/DC Converters
Isolated Telecommunication Power Systems
Distributed Power Step-Down Converters
Offl ine Isolated Power Supplies
Industrial Control Systems
Automotive and Heavy Equipment


Specifications

Supply Voltage
VIN ........................................................................20V
FB Voltage .................................................... 0.3V to 6V
OPTO Short-Circuit Duration ............................ Indefi nite
Operating Junction Temperature Range (Note 2)
.......................................................... 40°C to 125°C
Storage Temperature Range ................... 65°C to 150°C
Lead Temperature (Soldering, 10 sec) .................. 300°C

Description

The LT®4430 drives the optocoupler that crosses the galvanic barrier in an isolated power supply. The IC contains a precision-trimmed reference, a high bandwidth error amplifi er, an inverting gain of 6 stage to drive the optocoupler and unique overshoot control circuitry.

The LT4430's 600mV reference provides ±0.75% initial accuracy and ±1.25% tolerance over temperature. A high bandwidth 9MHz error amplifi er permits simple frequency compensation and negligible phase shift at typical loop crossover frequencies. The optocoupler driver provides 10mA of output current and is short-circuit protected.
A unique overshoot control function prevents output overshoot on startup and short-circuit recovery with a
single capacitor.

The LT4430 is available in the low profi le 6-lead SOT-23 package.