The UCC28180 is a flexible and easy-to-use 8-pin active power factor correction (PFC) controller that operates in continuous conduction mode (CCM) to provide high power factor, low current distortion, and excellent voltage regulation for boost pre-regulators in AC-DC front ends. This controller is suitable for universal AC input systems in the range of 100W to several kilowatts, with a switching frequency programmable from 18kHz to 250kHz to easily support power MOSFET and IGBT switching. The integrated 1.5A and 2A (SRC-SNK) peak gate drive output is internally clamped at 15.2V (typical), enabling fast turn-on and turn-off and easy management of external power switches without the need for buffer circuits.
By using average current mode control, low-distortion input current waveform shaping is achieved without input line sensing, reducing the external component count. In addition, the controller features a reduced current sensing threshold, making it convenient to use low-value shunt resistors to minimize power dissipation — particularly important in high-power systems. To achieve low current distortion, this controller also features a trimmed current loop regulation circuit designed to eliminate associated errors.
A simple external network enables flexible compensation of current and voltage control loops. Furthermore, the UCC28180 provides an enhanced dynamic response circuit based on the voltage feedback signal, which improves response to fast load transients under overvoltage and undervoltage conditions. The unique VCOMP discharge circuit integrated in the UCC28180 activates when the voltage feedback signal exceeds V0VP_L, enabling the control loop to quickly settle and avoid triggering the overvoltage protection function. When overvoltage protection is triggered, PWM shutdown often causes audible noise. Controlled soft-start gradually regulates the input current during startup and reduces stress on the power switches. The controller provides multiple system-level protections, including VCC UVLO, peak current limiting, soft overcurrent protection, output open-loop detection, output overvoltage protection, and open-pin detection (VISNS). The trimmed internal reference provides precise protection thresholds and regulation setpoints. Users can control the low-power standby mode by pulling the VSENSE pin below 0.82V.