摘要
设计了一种用于原边反馈反激变换器的电压采样电路。该方案通过检测上一个周期的放电时间,确定本周期对电压进行采样的位置。电路具有延时采样功能,确保在采样时流过次边整流二极管的电流为零,消除由二极管正向压降引起的采样误差。采用0.5μm BiCMOS工艺,利用Hspice软件对电路进行仿真。仿真结果表明,采样电路能够在本周期放电时间的95%处采样,此刻整流二极管电流几乎为零,满足设计要求。
A voltage sampling circuit used in PSR flyback converters was presented. The sampling point of one＇s cycle was determined by the discharging time of last cycle. The sampling point was delayed to make sure that the current flowing through the rectifier diode at secondary side was zero when sampling, so that the error caused by forward voltage drop of rectifier diode could be eliminated. This circuit was based on 0. 5μm BiCMOS process, and was simulated with Hspice. Simulation results showed that the voltage was sampled at the 95% of current cycle discharging time, and at this moment the current flowing through the rectifier diode was almost zero. So the results met the requirement of design very well.
出处
《微电子学》
CAS
CSCD
北大核心
2015年第5期557-559,563,共4页
Microelectronics
基金
国家自然科学基金资助项目(61271090)
国家高技术研究发展(863)计划重大项目(2012AA012305)
关键词
原边反馈
反激变换器
电压采样
Primary side regulation
Flyback converter
Voltage sampling
