NCP4355 Secondary Side SMPS OFF Mode Controller for Low Standby Power Description NCP4355 Current Regulation ISNS VCC OTA Sink only V CC V REFC management I Power BIASV RESET SW3 V DD V DD V REF VSNS OTA FBC Sink only Voltage V ON/OFF REF Power Regulation RESET 0.9 x V I REF DRIVEON I BIASV Enabling VCC SW1 Off Mode Q S Detection 10%V CC Q R LED OFFDET SW2 1 kHz, 12% D.C. Oscillator GND PowerRESET Figure 1. Simplified Block Diagram NCP4355A VCC V CC management I BIASV Power RESET SW3 V DD V DD V REF VSNS FBC OTA Sink only Voltage V REF Power ON/OFF Regulation RESET 0.9 x V I REF DRIVEON I BIASV Enabling VCC SW1 Off Mode Q S Detection 10%V CC Q R LED OFFDET SW2 1 kHz, 12% D.C. VMIN Oscillator GND PowerRESET V REFM Min Output Voltage Figure 2. Simplified Block Diagram NCP4355B