RT7311BGS

RT7311B Phase-Cut Dimmable Primary-Side Regulation LED Driver Controller with Active PFC and Integrated Power MOSFET General Description Features Integrated Power MOSFET The RT7311B consists of a high voltage power Supporting Phase-Cut Dimmers MOSFET and a high-performance phase-cut dimmable Tight LED Current Regulation constant current LED driver. I. It supports high power No Opto-Coupler and TL431 Required factor across a wide range of line voltages, and it drives Power Factor Correction (PFC) the converter in the Quasi-Resonant (QR) mode to Quasi-Resonant achieve higher efficiency. By using Primary Side Maximum/Minimum Switching Frequency Regulation (PSR), RT7311B controls the output current Clamping accurately without a shunt regulator and an Maximum/Minimum On-Time Limitation opto-coupler at the secondary side, reducing the Wide VDD Range (up to 25V) external component count, the cost, and the volume of Multiple Protection Features : the driver board. LED Open-Circuit Protection The RT7311B supports phase-cut dimmers, including LED Short-Circuit Protection leading-edge (TRIAC) and trailing-edge dimmers. Output Diode Short-Circuit Protection RT7311B embeds comprehensive protection functions VDD Under-Voltage Lockout for robust designs, including LED open circuit protection, VDD Over-Voltage Protection LED short circuit protection, output diode short-circuit Over-Temperature Protection protection, VDD Under-Voltage Lockout (UVLO), VDD Cycle-by-Cycle Current Limitation Over-Voltage Protection (OVP), Over-Temperature Protection (OTP), and cycle-by-cycle current limitation. Application Phase-Cut Dimmable LED luminaries Simplified Application Circuit Flyback Converter Tapped-Inductor Buck-Boost Converter L1 BD TX 1 D Line L1 BD TX OUT VOUT- 1 Line V OUT+ R DMR2 R ST1 N 2 C R OUT DMR2 R ST1 NP NS C DOUT OUT C Q1 X C M V C Q1 R C OUT+ X C DMR1 DMR M D V Neutral Z N R C OUT- 1 DMR1 DMR D Neutral Z D RT7311B ST D ST DRAIN RT7311B SOURCE DRAIN VDD VDD R SOURCE CVDD CS CVDD R GND CS COMP CCOMP GND COMP CCOMP ZCD R ZCD2 ZCD R NA ZCD2 N 3 RZCD1 D AUX R ZCD1 DAUX Copyright 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. DS7311B-00 October 2016 www.richtek.com 1 RT7311B Ordering Information Marking Information RT7311B RT7311BGS : Product Number YMDNN : Date Code Package Type RT7311B S : SOP-8 GSYMDNN Lead Plating System G : Green (Halogen Free and Pb Free) Pin Configuration Note : (TOP VIEW) Richtek products are : RoHS compliant and compatible with the current 8 VDD GND requirements of IPC/JEDEC J-STD-020. 2 7 COMP NC 3 6 ZCD DRAIN Suitable for use in SnPb or Pb-free soldering processes. 4 SOURCE 5 DRAIN SOP-8 Functional Pin Description Pin No. Pin Name Pin Function Supply voltage (V ) input. The controller will be enabled when V exceeds DD DD 1 VDD V and disabled when V is lower than V . TH ON DD TH OFF 2 COMP Compensation node. Output of the internal trans-conductance amplifier. Zero current detection input. This pin is used to sense the voltage at auxiliary 3 ZCD winding of the transformer. 4 SOURCE Source terminal of the integrated power MOSFET. 5, 6 DRAIN Drain terminal of the integrated power MOSFET. 7 NC No internal connection. 8 GND Ground of the controller. Copyright 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. www.richtek.com DS7311B-00 October 2016 2