The Infineon ICE2QR0665ZXKLA1 is an offline flyback switching regulator from the CoolMOS™ and CoolSET™-Q1 series, integrating a 650 V breakdown CoolMOS power switch with a PWM controller in a single through-hole package. It delivers up to 79 W in isolated flyback topologies, switching at 52 kHz with a fixed 50% duty cycle. Typical applications include auxiliary power supplies for industrial systems, AC-DC adapters, and bias supplies in motor drives or home appliances where a compact, single-chip solution is needed.
The 79 W output power rating defines the transformer core size and the secondary-side rectifier selection. The 650 V breakdown voltage on the internal CoolMOS switch gives headroom for universal AC input with reflected voltage and leakage spike margin. The 52 kHz switching frequency is a standard sweet spot: high enough to keep the transformer small, low enough that a simple RC snubber on the drain node handles ringing without excessive loss. The 10.5 V to 27 V Vcc range allows the IC to run off an auxiliary winding or a small bias supply without an external linear regulator. Fault protections include current limiting, overload, over-temperature, and over-voltage — all integrated, so no external comparators or watchdog circuits are needed. The 18 V startup voltage ensures the IC stays off until the bulk capacitor charges sufficiently, preventing hiccup on brownout conditions.