基于Si9122A的同步整流输出DC/DC变换器

DC/DC Converter based on Si9122A with Secondary Synchronous Output

研制了半桥结构的DC/DC变换器。采用带同步整流驱动输出的新型半桥控制芯片Si9122A实现了对变换器中初级开关管和次级同步整流管的PWM控制。该变换器电路结构简洁,控制调整方便。由于输出整流电路中采用低导通电阻的同步整流MOSFET替代了肖特基二极管,芯片自带同步整流管驱动信号,解决了自驱动方式信号差和外驱动方式电路复杂的问题。最后给出了实验结果。

A DC/DC converter based on half-bridge controller Si9122A is developed.The half-bridge controller with integrated secondary synchronous rectification driver is uesd for secondary synchronous rectification control with the considerable merits of succinct circuit structure and controllable parmeters.The diodes used in the rectifying circuit is repiaced by the synchronous rectifying MOSFET with very low on-state resistance,the efficiency of the converter can be improved. The designcircuits and the experimental results are showed and analyzed.