描述 Description

The AP3108LS is a Current Mode PWM controller specially designed for offline power supply that requires ultra-low standby power, high power density and comprehensive protection. The AP3108LS coordinating with Diodes Incorporated’s secondary side controller,such as the AP4320, can be applied in the situation that requires for constant CC and constant CV. The maximum switching frequency of the AP3108LS is set at 65kHz. The switching frequency can be modulated through green mode, in which it will smoothly decrease along with the decreasing load. This will cause the minimum switching frequency to be clamped at about 22kHz to avoid audible noise. The AP3108LS provides an inner high-voltage start-up function through HV pin which can save the use of the external start-up resistor, reducing the standby loss. The HV pin also realizes X-CAP discharge function. This is a useful function for power saving when an X-CAP is connected to a system, for it will discharge the X-CAP when the AC line voltage is off automatically without the need for extra discharge resistors. The AP3108LS integrates a VCC LDO circuitry, allowing the LDO to regulate the wide range VCC_IN, which is rectified from auxiliary winding to an acceptable value. This makes the AP3108LS a good choice in wide range output voltage application. There are also versatile system protections provided by AP3108LS, such as secondary side OVP, secondary side UVP, constant output current limit, cycle-by-cycle current limit, brown-out protection, programmable external OTP, etc.