Description
The NCP4355 is a secondary side SMPS controller designed for use in applications which require extremely low no load power consumption. The device is capable of detecting “no load” conditions and entering the power supply into a low consumption OFF mode. During OFF mode, the primary side controller is turned off and energy is provided by the output capacitors thus eliminating the power consumption required to maintain regulation. During OFF mode, the output voltage relaxes and is allowed to decrease to an adjustable level. Once more energy is required, the NCP4355 automatically restarts the primary side controller by ONOFF current that flows through ONOFF optocoupler. The NCP4355 controls the primary controller with an “Active ON” signal, meaning that it only drives optocoupler current during ON mode to minimize consumption during OFF mode.

FEATUREs
• Operating Input Voltage Range: 3.5 V to 36.0 V
• Supply Current < 100 μA
• ±0.5% Reference Voltage Accuracy (TJ = 25°C)
• Constant Voltage and Constant Current (A and C versions) Control Loop
• Indication LED PWM Modulated Driver (except NCP4355C)
• These Devices are Pb−Free, Halogen Free/BFR Free and are RoHS Compliant

Typical Applications
• Offline Adapters for Notebooks, Game Stations and Printers
• High Power AC−DC Converters for TVs, Set−Top Boxes, Monitors etc.