As discussed in application note, AN728, the Si9113 power supply controller is an ideal choice for ISDN terminal equipment, where high efficiency at a low power level is one of most important criteria. Therefore, Vishay Siliconix has developed versions of a dual output flyback application. The Si9113D2 uses the auxiliary output (VCC bootstrap winding) for sensing. Both VOUT1 (3.3 V) and VOUT2 (40 V)
