RT7304 Datasheet, PDF (1/14 Pages) Richtek Technology Corporation – Primary-Side-Regulation LED Driver Controller with Active PFC

®
RT7304
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.
Marking Information
0H=DNN
0H= : Product Code
DNN : Date Code
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 Voltage 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 Limit
 RoHS Compliant and Halogen Free
Applications
 AC/DC LED Lighting driver
Simplified Application Circuit
Flyback Converter
Buck-Boost Converter
Line
Neutral
BD
CSIN
RST
RT7304
RG
GD
VDD
RPC
CS
CVDD
CCOMP
COMP
GND
ZCD
DAUX
TX1 DOUT
VOUT+
COUT
Line
VOUT-
Q1
Neutral
RCS
RZCD2
RZCD1
BD
CSIN
RST
RT7304
RG
GD
VDD
RPC
CS
CVDD
CCOMP
COMP
GND
ZCD
DAUX
TX1
VOUT-
DOUT
COUT
VOUT+
Q1
RCS
RZCD2
RZCD1
Copyright ©2015 Richtek Technology Corporation. All rights reserved.
DS7304-04 February 2015
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
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