PFC controller in Continuous Conduction mode — 65 kHz fixed frequency
The NCP1655ADR2G is a multi-mode power factor correction controller from onsemi, operating in Continuous Conduction (CCM) at a fixed 65 kHz switching frequency. CCM mode means the inductor current never drops to zero during the switching cycle — this reduces peak current stress on the MOSFET and output diode, but requires a larger boost inductor compared to boundary or discontinuous modes. The 65 kHz rate is a reasonable middle ground between magnetics size and switching losses for offline supplies in the 100 W to 1 kW range. Supply voltage range is 8.5 V to 11.25 V, so the controller runs from a regulated auxiliary rail — not directly off the bulk capacitor.
9-SOIC package — board-fit and sourcing
Housed in a 10-SOP (0.154" wide, 3.90 mm body) with 9 leads, the supplier device package is 9-SOIC. The 10-pin SOP footprint with one pin omitted is a common variant — the PCB land pattern matches a standard SOIC-10 layout, leaving the missing pin position unpopulated.
Active lifecycle — no last-time-buy pressure
Onsemi lists the NCP1655ADR2G as Active. Availability and current pricing confirmed at RFQ.