The AP3106 is a high voltage start-up,current mode PWMcontroller with green-mode power-saving operation. The PWM switching frequency at normal operation is externally programmable and trimmed to a narrow range. The AP3106 integrates a proprietary internal frequency dithering function that helps to reduce EMI emission of a power supply with minimum line filters used. To minimize the standby power consumption, a proprietary adaptive green-mode function is available to implement frequency modulation under light-load conditions. To avoid acoustic noise problems, the minimum PWM frequency is set at about 26kHz. The AP3106 integrates a lot of functions such as the Lead-Edge Blanking (LEB) of the current sensing, internal slope compensation, line compensation, and several protection features that include cycle-by-cycle current limit (OCP), over voltage protection, OTP, OLP and brownout protection.