Diode’s AP3118 high-voltage PWM controller is specially designed for an offline power supply that requires ultra-low standby power, high-power density, and comprehensive protection. Coordinating with secondary USB PD controller can provide a total USB PD solution. The PWM switching frequency at normal operation is internally fixed (about 65 kHz). AP3118 supports transient peak power excursion. At peak load, the frequency will be increased from 65 kHz to 130 kHz to meet the requirement of output power. The duration time is internally set to 30 ms.

The AP3118 provides an inner high voltage start-up function through the HV pin which can reduce the standby loss. The HV pin also realizes X-CAP discharge function. When an X-CAP is connected to a system, it will automatically discharge the X-CAP when the AC line voltage is off without the need for extra discharge resistors. The AP3118 integrates V_CC LDO circuitry, allowing the LDO to regulate the wide range V_{CC_IN} to an acceptable value making it a good choice in wide range output voltage application. There are also versatile system protections provided by AP3118, such as secondary side OVP, secondary side UVP, constant output current limit, cycle-by-cycle current limit (OCP), brown-out protection, programmable external OTP, and others.