Power factor correction converter, method of operating power converter, and controller

The invention discloses a power factor correction converter, a method of operating a power converter, and a controller. One example is a method of operating a power converter, the method comprising: charging a first phase inductance of a first boost converter, and then discharging the first phase inductance, the charging and discharging defining a first switching period of the first boost converter; asserting, during the first switching period, a synch-2 signal based on a duration of a previous switching period of the first boost converter and an offset value; asserting a valley-2 signal when a current through a second phase inductance of the second boost converter reaches a predetermined valley current during the first switching period; in response to the assertion of the synch-2 signal and the valley value-2 signal, charging the second phase inductance, and then discharging the second phase inductance; and modifying the offset value in response to a relative timing of the assertion of the synch-2 signal and