RT7304

®

DS7304-04 February 2015

www.richtek.com

1

©

Copyright 2015 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

Primary-Side-Regulation LED Driver Controller

with Active PFC

General Description

The RT7304 is a constant current LED driver with active

power factor correction. It supports high power factor

across a wide range of line voltages, and it drives the

converter in the Quasi-Resonant (QR) mode to achieve

higher efficiency. By using Primary Side Regulation (PSR),

the RT7304 controls the output current accurately without

a shunt regulator and an opto-coupler at the secondary

side, reducing the external component count, the cost,

and the volume of the driver board.

The RT7304 embeds comprehensive protection functions

for robust designs, including LED open-circuit protection,

LED short-circuit protection, output diode short-circuit

protection, VDD Under-Voltage lockout (UVLO), VDD Over-

Voltage Protection (VDD OVP), Over-Temperature

Protection (OTP), and cycle-by-cycle current limitation.

Features

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Tight LED Current Regulation

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No Opto-Coupler and TL431 Required

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Power Factor Correction (PFC)

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Quasi-Resonant

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Maximum/Minimum

Switching

Frequency

Clamping

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Maximum/Minimum On-Time Limitation

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Wide VDD Voltage Range (up to 25V)

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Multiple Protection Features



LED Open-Circuit Protection

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LED Short-Circuit Protection

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Output Diode Short-Circuit Protection

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VDD Under-Voltage Lockout

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VDD Over-Voltage Protection

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Over-Temperature Protection

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Cycle-by-Cycle Current Limit

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RoHS Compliant and Halogen Free

Simplified Application Circuit

Applications

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AC/DC LED Lighting driver

Marking Information

Flyback Converter

Buck-Boost Converter

0H=DNN

0H= : Product Code

DNN : Date Code

GD

CS

VDD

RT7304

TX1

ZCD

Line

Neutral

BD

COMP

GND

Q1

GD

CS

VDD

RT7304

TX1

ZCD

Line

Neutral

BD

COMP

GND

Q1