Design Of High-voltage AC/DC LED Driver IC

LED has many advantages, such as energy-saving, environmental, long serviced, photoelectric efficiency and short-time started etc.. It is another lighting revolution and has made rapid progress these years. But the development is with challenge due to its electrical properties. The ability of LED integrated drive circuit, hereinafter referred to LED circuit, is a key to realize the stability of LED. It is asked for a more precise output current control. While the present LED circuit has intensively used a method of voltage driving. It has a poor constant-current ability which leads to a short LED life.As to two categories, DC and AC LED circuit, things are different. DC LED circuit is a mature technic which has been developed a lot. But AC LED circuit is technically immature at present. Especially the Step-down AC LED circuit which is aimed at electric supply. Its power volume is too large. Its output current is unstable. And its efficiency is low. Because it is widely used those methods called Ac input capacitance step-down and power frequency transformer step-down. Therefore it is a key and difficult point in this area.So Based on CSMC’s 700 V BCD process designed a high-voltage integrated AC/DC LED driver IC, integrated 700 V MOSFET, can be directly mains input, constant current output and power factor correction.From the TOP-DOWN, from the high_voltage integrated AC / DC LED driver IC design index starting design high_voltage integrated AC / DC LED driver IC power structure; design pin arrangement and pin definitions; determining circuit structure; module circuit design and simulation, to validate the final design through simulation top-level circuit. Based on the high-voltage integrated AC/DC LED driver IC design requirements, theoretically proved that the use of continuous conduction mode can be higher compared to the critical mode power factor, and in the circuit design on a number of key modules have innovative design, for example, with a secondary bandgap reference voltage output, linear low input voltage high linearity OTA. In this paper, high-voltage integrated AC / DC LED driver IC inside the key modules in different process corners, voltage and temperature conditions on the circuit simulation, results are consistent with high_voltage integrated AC/DC LED driver IC design requirements.