RT7305

Copyright © 2014 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation

DS7305-00

July

2014

www.richtek.com

1

Primary-Side

Regulation

LED

Driver

Controller

with

Active-PFC and Integrated Power MOSFET

General Description

The RT7305 consists of a high voltage power MOSFET

and a high-performance 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), RT7305 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.

RT7305 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

(OVP),

Over-Temperature

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

Applications



AC/DC LED Lighting Driver

Features



Integrated 620V Power MOSFET



Tight LED Current Regulation



No Opto-Coupler and TL431 Required



Power Factor Correction (PFC)



Quasi-Resonant



Maximum/Minimum Switching Frequency

Clamping



Maximum/Minimum on-Time Limitation



Wide VDD Range (up to 25V)



Multiple Protection Features



LED Open-Circuit Protection



LED Short-Circuit Protection



Output Diode Short-Circuit Protection



VDD Under-Voltage Lockout



VDD Over-Voltage Protection



Over-Temperature Protection



Cycle-by-Cycle Current Limitation



RoHS Compliant and Halogen Free

Simplified Application Circuit

Flyback Application Circuit

COMP

DRAIN

RT7305

VDD

Line

Neutral

ZCD

CS

GND

SOURCE

Buck-Boost Application Circuit

COMP

DRAIN

RT7305

VDD

ZCD

Line

Neutral

CS

GND

SOURCE