NCP1201

NCP1201 PWM Current- Mode Controller for Universal Off- Line Supplies Featuring Low Standby Power with Fault Protection Modes Housed in SOIC--8 or PDIP--8 package, the NCP1201 enhances the previous NCP1200 series by offering a reduced optocoupler current with additional Brownout Detection Protection (BOK). Similarly, the circuit allows the implementation of complete off--line AC--DC adapters, battery chargers or Switchmode Power Supplies (SMPS) where standby power is a key parameter. The NCP1201 features efficient protection circuitry. When in the presence of a fault (e.g. failed optocoupler, overcurrent condition, etc.) the control permanently disables the output pulses to avoid subsequent damage to the system. The IC only restarts when the user cycles the mains power supply. With the low power internal structure, operating at a fixed 60 or 100 kHz, the controller supplies itself from the high--voltage rail, avoiding the need of an auxiliary winding. This feature naturally eases the designer’s task in battery charger applications. Finally, current--mode control provides an excellent audio--susceptibility and inherent pulse--by--pulse control. When the load current falls down to a pre--defined setpoint (VSKIP) value, e.g. the output power demand diminishes, the IC automatically enters the skip cycle mode and can provide excellent efficiency under light load conditions. The skip mode is designed to operate at relatively lower peak current so that acoustic noise that commonly ...