The AP3988 provides primary-side control, eliminating the need need for opto-couplers and secondary-side control circuitry. This reduces component count, board space requirements and cost. Primary-side regulation also enables higher efficiency with less heat generated in the power supply, increasing reliability. The side-switching controller also features improved output voltage and current accuracy, enhanced over-voltage and short-circuit protection and better EMC performance (achieved by frequency dithering).
The primary-side switcher integrates 700VCBO transistors and features typical start-up current of just 0.2µA, integral cable voltage drop compensation of 5% of nominal voltage and adjustable line voltage compensation.
The AP3988 controller is available in now in an SO-7 package.