Improve the soft start performance design of UCC2806x with external circuits

The probe capacitor polarity needle has a head diameter of 5.8. The total length of the 7-pin and 12-pin needles is 5.

Overview:
This application note describes how to use an external circuit to improve the soft-start performance of the UCC28060 and UCC28061 PFC controllers. Using a soft-start circuit can reduce the large startup current and reduce the PFC output overshoot voltage.

With its high efficiency, low ripple and excellent electromagnetic interference performance. The UCC28060 and UCC28061 interleaved power factor correction controllers are widely favored by many users. However, if the starting current is too large, the power supply can easily enter the fault protection state or even be damaged. In addition, the PFC output voltage should also be a small overshoot voltage to improve the safety of the switching components and downstream DC/DC converter circuits.

External soft start circuit configuration of UCC2806x

(Please read the PDF for details)