New Industry Products

Primary Side Regulated Switching Mode Power Supply Controller

August 15, 2020 by Hailey Stewart

This article highlights Diodes Incorporated AP3781 that is a high-performance AC/DC power supply controller for battery charger and adapter applications.

Diodes Incorporated announces AP3781, a high-performance AC/DC power supply controller for battery charger and adapter applications. The controller regulates the output voltage and current in the primary side by Pulse Frequency Modulation in Discontinuous Conduction Mode (DCM).


Primary Side Regulated Switching Mode Power Supply Controller
Image courtesy of Diodes Incorporated

The AP3781 operates in Pulse Frequency Modulation (PFM) mode and peak current Amplitude Modulation (AM) mode to form a fine tune frequency curve within the whole power range. AP3781 can achieve high efficiency and improve audible noise.

The AP3781 provides comprehensive protections without additional circuitry. It contains VCC over voltage protection, output over voltage protection, output under voltage protection, output short circuit protection, cycle-by-cycle current limit, open loop protection, external OTP and internal OTP.

The AP3781 is packaged in a SO8.


About Diodes Incorporated

Diodes Incorporated,  a Standard and Poor’s SmallCap 600 and Russell 3000 Index company, is a leading global manufacturer and supplier of high-quality application-specific standard products within the broad discrete, logic, analog and mixed-signal semiconductor markets. Diodes serve the consumer electronics, computing, communications, industrial, and automotive markets. Diodes’ products include diodes, rectifiers, transistors, MOSFETs, protection devices, function-specific arrays, single gate logic, amplifiers and comparators, Hall-effect and temperature sensors, power management devices, including LED drivers, AC-DC converters and controllers, DC-DC switching and linear voltage regulators, and voltage references along with special function devices, such as USB power switches, load switches, voltage supervisors, and motor controllers. Diodes also have timing, connectivity, switching, and signal integrity solutions for high-speed signals. Diodes’ corporate headquarters and Americas’ sales office are located in Plano, Texas and Milpitas, California. Design, marketing, and engineering centers are located in Plano; Milpitas; Taipei, Taiwan; Taoyuan City, Taiwan; Zhubei City, Taiwan; Manchester, England; and Neuhaus, Germany. Diodes’ wafer fabrication facility is located in Manchester, with an additional facility located in Shanghai, China. Diodes has assembly and test facilities located in Shanghai, Jinan, Chengdu, and Yangzhou, China, as well as in Hong Kong, Neuhaus, and Taipei. Additional engineering, sales, warehouse, and logistics offices are located in Taipei; Hong Kong; Manchester; Shanghai; Shenzhen, China; Seongnam-si, South Korea; and Munich, Germany, with support offices throughout the world.