The UCC28180 is a flexible and easy-to-use, 8-pin, active Power-Factor Correction (PFC)
controller that operates under Continuous Conduction Mode (CCM) to achieve high Power Factor, low
current distortion and excellent voltage regulation of boost pre-regulators in AC - DC front-ends.
The controller is suitable for universal AC input systems operating in 100-W to few-kW range with
the switching frequency programmable between 18 kHz to 250 kHz, to conveniently support both power
MOSFET and IGBT switches. An integrated 1.5-A and 2-A (SRC-SNK) peak gate drive output, clamped
internally at 15.2 V (typical), enables fast turn-on, turn-off, and easy management of the external
power switch without the need for buffer circuits.
Low-distortion wave shaping of the input current using average current mode control is
achieved without input line sensing, reducing the external component count. In addition, the
controller features reduced current sense thresholds to facilitate the use of small-value shunt
resistors for reduced power dissipation, especially important in high-power systems. To enable low
current distortion, the controller also features trimmed internal current loop regulation circuits
for eliminating associated inaccuracies.
Simple external networks allow for flexible compensation of the current and voltage
control loops. In addition, UCC28180 offers an enhanced dynamic response circuit that is based on
the voltage feedback signal to deliver improved response under fast load transients, both for
output overvoltage and undervoltage conditions. An unique VCOMP discharge circuit provided in
UCC28180 is activated whenever the voltage feedback signal exceeds VOVP_L
thus allowing a chance for the control loop to stabilize quickly and avoid encountering the
overvoltage protection function when PWM shutoff can often cause audible noise. Controlled soft
start gradually regulates the input current during start-up and reduces stress on the power
switches. Numerous system-level protection features available in the controller include VCC UVLO,
peak current limit, soft overcurrent, output open-loop detection, output overvoltage protection and
open-pin detection (VISNS). A trimmed internal reference provides accurate protection thresholds
and regulation set-point. The user can control low-power standby mode by pulling the VSENSE pin
below 0.82 V.