High Voltage Switching Regulator for Offline SMPS

The NCP1028 offers a new solution targeting output power levels from a few watts up to 15W in a universal mains flyback application. Our proprietary high-voltage technology lets us include a power MOSFET together with a startup current source, all directly connected to the bulk capacitor. To prevent lethal runaway in low input voltage conditions, an adjustable brown-out circuitry blocks the activity until sufficient input level is reached. Current-mode operation together with an adjustable ramp compensation offers superior performance in universal mains applications. Protection wise, a timer detects an overload or a short-circuit and stops all operations, ensuring a safe auto-recovery, low duty cycle burst operation. An integrated, auto-recovery. Finally, a great RDS(on) figure makes the circuit an excellent choice for standby/auxiliary offline power supplies or applications requiring higher output power levels.