RT7304A Datasheet, PDF (1/16 Pages) Richtek Technology Corporation – Primary-Side Regulation LED Driver Controller

RT7304A
Primary-Side Regulation LED Driver Controller with Active-PFC
General Description
The RT7304A 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 RT7304A 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 RT7304A 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)
 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
Buck-Boost Converter
Line
Neutral
BD
TX1
V_OUT-
C_IN
R_ST
VDD
C_VDD
RT7304A _GD
C_OUT
D_OUT
Q1
V_OUT+
COMP
C_COMP
R_PC
CS
R_CS
ZCD
GND
D_AUX
R_ZCD1
R_ZCD2
Copyright © 2016 Richtek Technology Corporation. All rights reserved.
DS7304A-01 May 2016
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
1