PFC controller in Critical Conduction mode
The TC33368VOM is a power factor controller from Microchip Technology's TC33368 series, designed to operate in Critical Conduction (CRM) mode. CRM is the standard topology for medium-power PFC stages — the inductor current ramps to zero each cycle, which simplifies the control loop and reduces the reverse-recovery loss in the boost diode compared to continuous conduction mode. Rated for a 16V supply rail with a 16 mA startup current, the part is biased from an auxiliary winding or a downstream regulator. The -25°C to 125°C operating range covers industrial ambient conditions, including motor-drive cabinets and lighting ballasts where the controller sits near the heatsink.
16-SOIC surface-mount package
The 16-SOIC footprint is common — no special pad geometry or thermal-via array is required unless the PFC stage dissipates more than about 1 W in the controller itself.