FAN7930C is an active power factor correction (PFC) controller for boost PFC applications operating in critical conduction mode (CRM). It uses voltage-mode PWM to compare the internal ramp signal with the error amplifier output to generate the MOSFEt-off signal.
Application program
Since the voltage mode CRM PFC controller does not require commutating AC line voltage information, it saves the power loss of the input voltage sensing network necessary for the current mode CRM PFC controller. FAN7930C provides overvoltage protection (OVP), open feedback protection, overcurrent protection (OCP), input voltage loss detection and undervoltage lock protection (UVLO).
The PFC-Ready pin can be used to trigger other power levels when the PFC output voltage reaches the appropriate level. FAN7930C can be disabled if the INV pin voltage is below 0.45V and the operating current drops to a very low level. Using a new time-varying control method, total harmonic distortion (THD) is lower than the traditional CRM boost PFC ic.
Functional Block Diagram
