NCP4354A

NCP4353, NCP4354 Secondary Side SMPS OFF Mode Controller for Low Standby Power The NCP4353/4 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 NCP4353/4 automatically restarts the primary side controller. The NCP4353/4 controls the primary side controller with an “Active OFF” signal, meaning that it drives optocoupler current during OFF mode to pull−down the FB pin of the primary controller. During normal power supply operation, the NCP4353/4 provides integrated voltage feedback reg...