FAN7930B Critical Conduction Mode PFC Controller November 2013 FAN7930B Critical Conduction Mode PFC Controller Features Description Additional OVP Detection Pin The FAN7930B is an active power factor correction (PFC) controller for boost PFC applications that V -Absent Detection IN operate in critical conduction mode (CRM). It uses a Maximum Switching Frequency Limitation voltage-mode PWM that compares an internal ramp signal with the error amplifier output to generate a Internal Soft-Start and Startup without Overshoot MOSFET turn-off signal. Because the voltage-mode Internal Total Harmonic Distortion (THD) Optimizer CRM PFC controller does not need rectified AC line voltage information, it saves the power loss of an input Precise Adjustable Output Over-Voltage Protection voltage sensing network necessary for a current-mode Open-Feedback Protection and Disable Function CRM PFC controller. Zero Current Detector (ZCD) FAN7930B provides over-voltage protection (OVP), open-feedback protection, over-current protection 150 s Internal Startup Timer (OCP), input-voltage-absent detection, and under- MOSFET Over-Current Protection (OCP) voltage lockout protection (UVLO). The additional OVP pin can be used to shut down the boost power stage Under-Voltage Lockout with 3.5 V Hysteresis when output voltage exceeds OVP level due to the Low Startup and Operating Current resistors that are connected at INV pin are damaged. The FAN7930B can be disabled if the INV pin voltage is Totem-Pole Output with High State Clamp lower than 0.45 V and the operating current decreases to a very low level. Using a new variable on-time control +500/-800 mA Peak Gate Drive Current method, total harmonic distortion (THD) is lower than in 8-Pin, Small-Outline Package (SOP) conventional CRM boost PFC ICs. Applications Related Resources Adapter AN-8035 Design Consideration for Boundary Conduction Mode PFC Using FAN7930 Ballast LCD TV, CRT TV SMPS Ordering Information Operating Packing Part Number Top Mark Package Temperature Range Method FAN7930BMX G -40 to +125C FAN7930BG 8-Lead, Small-Outline Package (SOP) Tape & Reel 2010 Fairchild Semiconductor Corporation www.fairchildsemi.com FAN7930B Rev. 1.0.3 FAN7930B Critical Conduction Mode PFC Controller Application Diagram DC OUTPUT Vcc FAN7930B Line Filter 7 8 Out V CC 4 CS 5 ZCD AC INPUT 1 INV 3 COMP 2 OVP GND 6 Figure 1. Typical Boost PFC Application Internal Block Diagram VCC H:open VREF 2.5VREF 8 V CC V - CC VZ Internal V BIAS reset Bias + VTH(S/S) 8.5 12 5 ZCD - V CC + Restart Gate Tmer V TH(ZCD) 7 OUT Driver f MAX Limit V O(MAX) THD S Q Optimized Control Range Sawtooth + Compensation Generator R Q - 40k W Startup without + 4 CS Overshoot 8pF - 1 - INV V CS LIM V REF V REF 6 GND Stair + Step Clamp Circuit reset V Absent IN 3 COMP disable disable Thermal Shutdown - 0.35 0.45 V REF 2.5 2.675 + 2 INV open V OVP OVP,LH disable OVP + 2.5 2.88 - Figure 2. Functional Block Diagram 2010 Fairchild Semiconductor Corporation www.fairchildsemi.com FAN7930B Rev. 1.0.3 2 Clamp Circuit