Abstract: Some embodiments relate an integrated circuit (IC) including a first substrate. An interconnect structure is disposed over the first substrate. The interconnect structure includes a plurality of metal features that are stacked over one another. A lowermost metal feature of the plurality of metal features is closest to the first substrate, an uppermost metal feature of the plurality of metal features is furthest from the first substrate, and intermediate metal features are disposed between the lowermost metal feature and the uppermost metal feature. A recess extends into the interconnect structure and terminates at a bond pad. A lower surface of the bond pad directly contacts an upper surface of the lowermost metal feature.

Abstract: A power factor correction (PFC) converter comprises an inductor, a main switch, a voltage divider, a diode, and a controller. The main switch controls the inductor performing magnetization and demagnetization, wherein a voltage difference between two ends of the main switch is a switch voltage. The voltage divider divides the switch voltage and generates a division voltage. The controller performs the following operations periodically in general mode: turning on the main switch; turning off the main switch after the main switch is turned on for a period of time; obtaining the switch voltage according to the division voltage, and determining the period of time for which the main switch is turned on next time according to the switch voltage and a predetermined output voltage of the PFC converter; and obtaining an output voltage according to the switch voltage during a period of time after the main switch is turned off.