FAN7930B: CrCM PFC Controller, Programmable OVP

The FAN7930B is an active power factor correction (PFC) controller for boost PFC applications that operate in critical conduction mode (CRM). It uses a voltagemode PWM that compares an internal ramp signal with the error amplifier output to generate a MOSFET turn-off signal. Because the voltage-mode CRM PFC controller does not need rectified AC line voltage information, it saves the power loss of an input voltage sensing network necessary for a current-mode CRM PFC controller.

FAN7930B provides over-voltage protection, openfeedback protection, over-current protection, inputvoltage- absent detection, and under-voltage lockout protection. The additional OVP pin can be used to shut down the boost power stage when output voltage exceeds OVP level due to the resistors that are connected at INV pin are damaged. The FAN7930B can be disabled if the INV pin voltage is lower than 0.45V and the operating current decreases to a very low level. Using a new variable on-time control method, THD is lower than the conventional CRM boost PFC ICs.

Features

• Additional OVP Detection Pin
• Input Voltage Absent Detection Circuit
• Maximum Switching Frequency Limitation
• Internal Soft-Start and Overshoot-less Control
• Internal Total Harmonic Distortion (THD) Optimizer
• Precise Adjustable Output Over-Voltage Protection
• Open-Feedback Protection and Disable Function
• Zero Current Detector
• 150µs Internal Startup Timer
• MOSFET Over-Current Protection
• Under-Voltage Lockout with 3.5V Hysteresis
• Low Startup and Operating Current
• Totem-Pole Output with High State Clamp
• +500/-800mA Peak Gate Drive Current
• 8-Pin Small Outline Package (SOP)

Application Notes