onsemi NCP1655ADR2G, PFC Controller, 130 kHz, 35 V 9-Pin, SOIC

The ON Semiconductor NCP1655 is an innovative multimode power factor controller. The circuit naturally transitions from one operation mode to another depending the switching period duration so that the efficiency is optimized over the line/load range. In very−light−load conditions, the circuit can enter the soft−SKIP mode for minimized losses.

Fast line / load transient compensation (Dynamic Response Enhancer)
Large VCC operating range (9.5 V to 35 V)
Line range detection