FAN7529 PFC controller in critical conduction mode

. . . . . . FAN7529 is an active power factor correction (PFC) controller designed for boost PFC applications, operating in critical conduction mode (CRM). It uses PWM in voltage mode, comparing the internal ramp signal with the output of an error amplifier to generate a MOSFET turn-off signal. Since the PFC CRM controller in voltage mode does not require rectified AC line voltage information, it saves the power loss of the input voltage sensor network, which is necessary for the PFC CRM controller in current mode.The FAN7529 offers a number of protection functions, such as overvoltage protection, open feedback protection, overload protection and voltage lockout below the lockout level. The FAN7529 can be turned off if the INV pin voltage is lower than 0.45V and the operating current decreases to 65µA. Thanks to the new variable duration control method, THD is lower than that of conventional CRM boost PFC circuits. Low Total Harmonic Distortion (THD). Precise Surge Protection Control. Coupling Protection and Open Feedback Shutdown Function. Null Current Detector. Internal Start-up Timer 150 µs. MOSFET counter-current protection. Lower Voltage Lockout with 3.5V Hysteresis. Low Inrush Current (40 µA) and Operating Current (1.5 mA). Totem Pole Type Output with High State Clamp. Gateway Control Current with Peak Value of +500/-800mA. 8-pin SOP design. Applications: Power supply. Ballast. LCD TV, CRT TV. SMPS (Power Source for Inverters). . . INV: inverted error amplifier input. The output voltage of the PFC boost converter should be resistively divided to 2.5V.COMP: transconductance error amplifier output. Components for output voltage compensation should be connected between this pin and ground (GND).MOT: internal ramp slope setting. The voltage on this pin is kept at 2.9V. If a resistor is connected between this pin and GND, current flows out of this pin, and the slope of the internal ramp is proportional to this current.CS: overcurrent protection comparator input. The current of the MOSFET is measured using a measurement resistor, and the resulting voltage is applied to this pin. An internal RC filter is included to filter out switching noise.ZCD: zero current detection block input. If the voltage on this pin rises above 1.5V and then falls below 1.4V, the MOSFET will turn on.GND: ground potential for all pins. For proper operation, signal ground and power ground should be separated.OUT: gate control output. The maximum values of source and sink currents are +500mA and -800mA, respectively. For proper operation, the dissipation inductance on the gate control path should be minimized.. VCC: circuit power supply. The circuit current and the MOSFET control current are supplied via this pin..