650 V offline flyback switch for isolated AC-DC supplies
The ICE3B0565JG is an integrated offline flyback switch from Infineon's CoolMOS™ series, combining a 650 V avalanche-rated MOSFET with a current-mode PWM controller in a single PG-DSO-12 package. It targets isolated AC-DC converter designs — auxiliary power supplies for appliances, industrial control boards, and metering — where the 67 kHz switching frequency balances transformer size against EMI filter cost. The 75% maximum duty cycle and 10.3 V to 26 V Vcc range give the controller headroom to regulate through line dips without dropping out of UVLO.
Protection set and thermal envelope
Fault protection covers current limiting, open-loop, overload, over-temperature, and over-voltage — the controller latches off or auto-restarts depending on the fault type, which saves the designer from adding external supervisor circuitry for most single-fault conditions. Operating junction temperature spans -25°C to 130°C, so the part fits into enclosed power supplies where ambient inside the chassis reaches 85°C and the junction rises another 45°C above that under full load. The soft-start control feature limits inrush current during startup, reducing stress on the bulk capacitor and the downstream rectifier.
Housed in a 12-BSOP with exposed pad (PG-DSO-12), the surface-mount package requires a thermal land on the PCB to conduct heat from the die into the board copper — the exposed pad is the primary thermal path, not the leads. The 7.50 mm body width and 0.295-inch pitch match the standard DSO-12 footprint; the exposed pad sits on the bottom side and must be soldered to a copper island with at least four vias to the inner ground plane for effective thermal spreading.