LT4430

1

4430f

FEATURES

DESCRIPTIO

APPLICATIO S

TYPICAL APPLICATIO

Secondary-Side

Optocoupler Driver

galvanic barrier in an isolated power supply. The IC con-

tains a precision-trimmed reference, a high bandwidth

error amplifier, 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 amplifier 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 profile 6-lead SOT-23

package.

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48V Input Isolated DC/DC Converters

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Isolated Telecommunication Power Systems

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Distributed Power Step-Down Converters

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Offline Isolated Power Supplies

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Industrial Control Systems

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Automotive and Heavy Equipment

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600mV Reference (1.25% Over Temperature)

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Wide Input Supply Range: 3V to 20V

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Overshoot Control Function Prevents Output

Overshoot on Startup and Short-Circuit Recovery

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High Bandwidth Error Amplifier Permits Simple Loop

Frequency Compensation

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Ground-Referenced OptoCoupler Drive

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10mA OptoCoupler Drive with Current Limiting

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Simplified Isolated Synchronous Forward Converter

, LTC and LT are registered trademarks of Linear Technology Corporation.

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4430 TA01

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OPTO

GND

COMP

OC

FB

LTC3900

SYNC

CG

FG

LT4430

ISOLATION

BARRIER

LT1952

Isolated Flyback Telecom Converter

Startup with Overshoot Control

(See Schematic on Page 20)

50V/DIV

5V/DIV

OVERSHOOT CONTROL

IMPLEMENTED

t = 5ms/DIV

4430 TA01b

ThinSOT is a trademark of Linear Technology Corporation.