Specifically, the new NCP1050 device family advances ON Semiconductor's portfolio of power management Integrated Circuits (IC) for highly efficient power conversion applications. These devices consume less than 250 milliwatts during no-load conditions so facilitating compliance with global regulatory guidelines such as Energy Star and Blue Angel. Typical applications include auxiliary supplies for household appliances, portable battery chargers, cable and DSL modems, consumer electronic stand-by power supplies and other low power AC-to-DC converters.
These new ICs combine a 700-volt power-switch circuit and off-line start-up circuitry for 85 - 265 V AC power mains. The unique off-line start-up circuit design facilitates operation without an auxiliary transformer winding and associated components. In fact, the NCP1050 family operates with a minimum of external supply component. As such, power converter cost and size are minimized.
The NCP1050 family's oscillator circuit is limited to a 77 percent maximum duty cycle. An embedded turn-on latch allows the power switch to initiate conduction anywhere during its on-time window if the control input is toggled to begin power-switch conduction. This feature improves a power supply's load transient response versus competitive solutions. Power switch conduction terminates with a built-in turn-off latch by one of four methods: 1) the oscillator's normal off-time transition, 2) a control input pin transition, 3) a power switch over-current (Ilim) condition, or 4) device thermal shutdown (160°C)