RT7306

Copyright © 2015 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

DS7306-00

July

2015

www.richtek.com

1

Primary-Side Regulation Dimmable LED Driver Controller

with Active-PFC

General Description

The RT7306 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

RT7306

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.

RT7306 is compatible with analog dimming. The output

current can be modulated by the DIM pin. An in-house

design high voltage (HV) start-up device is integrated in

the RT7306 to minimize the power loss and shorten the

start-up time.

The

RT7306

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



Tight LED Current Regulation



No Opto-Coupler and TL431 Required



Power Factor Correction (PFC)



Compatible with Analog Dimming



Built-in HV Start-up Device



Quasi-Resonant



Maximum/Minimum Switching Frequency

Clamping



Maximum/Minimum on-Time Limitation



Wide VDD Range (up to 34V)



THD Optimization



Input-Voltage Feed-Forward Compensation



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

Applications



AC/DC LED Lighting Driver

Simplified Application Circuit

Flyback Application Circuit

BD

COMP

GD

RT7306

VDD

Line

Neutral

ZCD

CS

GND

TX1

HV

Q1

Analog

Dimming

Signal

DIM

Buck-Boost Application Circuit

BD

COMP

GD

RT7306

VDD

ZCD

TX1

Line

Neutral

CS

GND

HV

Q1

Analog

Dimming

Signal

DIM