Primary-Side-Regulation LED Driver Controller with Active PFC


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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.


Key Spec.
Status Active
Supply Voltage (min) (V)
Supply Voltage (max) (V)
Vin (min) (V) 12
Vin (max) (V) 25
Topology Buck-Boost;Flyback
Output C.C.
MOSFET Integrated No
Current Sense Threshold (mV)
Dimming Control
Features OCP;OVP
Package Type SOT-26
  • 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
TitleLast UpdateShareDownload
Primary-Side-Regulation LED Driver Controller with Active PFC2013/07/29
Technical Documents
TitleLast UpdateShareDownload
Power Solutions for LED Lighting Applications2018/11/22
Design Guidelines for RT7302 and RT7304 PSR LED Driver2016/04/08
Additional Documents
Title Last Update ShareDownload
AC/DC Isolated PSR Flyback Controllers for high Power Factor and low THD - RT7302, RT7304 2019/03/04
Evaluation Boards
TitleLast UpdateShareDownload
RT7304 Flyback Bulb 60Vout 130mA2018/11/01
RT7304 Flyback Bulb 45Vout 178mA2018/11/01
RT7304 Buck-boost Bulb 8W2018/11/01
RT7304 Buck-boost Edge T8 16W2018/11/01
Design Tool
TitleLast UpdateShare
RT7304 Flyback Design Tool 2019/04/16
Part NumberPackage TypePackage Qty.Free SampleBuy From Authorized Distributor
RT7304GESOT-263000 Request Buy from Distributor