Preliminary PT6917 Single Stage APFC Flyback LED Driver DESCRIPTION The PT6917 is a primary side regulation single stage Flyback and PFC controller for offline LED dimming applications. It achieves high power factor and accurate constant LED current with single power stage for isolated lighting applications. The PT6917 provides accurate LED current control from primary side information. Eliminating the secondary side feedback components and the opto-coupler significantly simplifies the LED lighting system design. The PT6917 integrates PFC function and the high PF value is achieved with constant on time operation. The PT6917 works in Quasi-Resonant switching mode to reduce the switching losses and improve the EMI performance. The multi-protection features of PT6917 greatly enhance the system reliability and safety. The PT6917 provides input over voltage protection, short LED protection, open LED protection, over temperature protection, cycle-by-cycle current limiting. FEATURES High PF>0.9 with single stage conversion Compatible with analog/PWM dimming modes Real-current control technique achieves accurate constant LED current Primary Side Regulation eliminates secondary feedback circuit Quasi-Resonant switching mode to achieve low switching losses 0.3V primary current sense reference voltage leads to a lower conduction loss ±5% output current accuracy Excellent line regulation and load regulation Reliable short LED and open LED protection System auto-restart function Low start-up current: 20μA typical VCC over voltage protection (OVP) VCC under voltage lockout (UVLO) Cycle by cycle primary side current limiting Over temperature protection (OTP) SOP-8 package APPLICATIONS LED tube lamp LED PAR lamp LED ceiling lamp Other LED lighting BLOCK DIAGRAM Tel: 886-66296288‧Fax: 886-29174598‧ http://www.princeton.com.tw‧2F, No. 233-1, Baociao Rd., Sindian Dist., New Taipei City 23145, Taiwan PT6917 APPLICATION CIRCUIT D1 D2 C2 NP R1 C1 R3 R4 T1 AC input C3 NS D3 R2 R5 D4 C4 U1 PWM Input R7 COMP DIM1 ZCD DIM2 PT6917 VCC CS R9 GND GD R8 C5 C6 R11 R10 Fig1: PWM Input Dimming D1 C2 D2 R1 C1 NP R3 R4 T1 AC input D3 R2 D4 C3 NS R5 C4 U1 R7 COMP 0-1.5V DIM1 ZCD DIM2 PT6917 VCC CS R9 GD GND R8 C5 R10 R11 Fig2: Analog Input Dimming PRE1.1 2 January 2015 PT6917 D1 D2 C2 NP R1 C1 R3 R4 T1 AC input D3 R2 D4 C3 NS R5 C4 U1 R7 COMP DIM1 ZCD DIM2 PT6917 VCC CS R9 GND GD R8 C5 C6 R10 R11 Fig3: Non-Dimming PRE1.1 3 January 2015 PT6917 ORDERINFORMATION Valid Part Number PT6917-S Package Type 8-PIN, SOP Top Code PT6917-S PIN CONFIGURATION 8 DIM1 7 DIM2 3 6 VCC 4 5 GD COMP 1 ZCD 2 CS GND PT6917-S PIN DESCRIPTION Pin Name Description Pin No. COMP Loop compensation pin. Inductor current zero-crossing detection pin. This pin also provides over voltage protection (OVP) and line regulation modification function. Current sense pin. Sense the inductor current when the switch is turned on. IC Ground. Gate driver pin. Connect to the gate of power MOSFET. Power supply pin. Analog dimming input pin, also Enable/Disable pin. PWM dimming input pin. Must be connected to GND if DIM1is not for dimming. 1 ZCD CS GND GD VCC DIM2 DIM1 PRE1.1 4 2 3 4 5 6 7 8 January 2015 PT6917 IMPORTANT NOTICE Princeton Technology Corporation (PTC) reserves the right to make corrections, modifications, enhancements, improvements, and other changes to its products and to discontinue any product without notice at any time. PTC cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a PTC product. No circuit patent licenses are implied. Princeton Technology Corp. 2F, 233-1, Baociao Road, Sindian Dist, New Taipei City 23145, Taiwan Tel: 886-2-66296288 Fax: 886-2-29174598 http://www.princeton.com.tw PRE1.1 9 January 2015