摘要
详细分析了峰值电流模式下脉宽限流不能起作用的原因;探讨了用于汽车电子系统的Buck变换器在输出短路恢复过程中出现的输出电压过冲及由于CCM模式响应慢导致COMP脚电压不能迅速放电的问题;讨论了短路时输出二极管和引线电压使电感逐渐饱和的过程。分析得出了输出过冲前沿尖峰产生于电感和输出电容的谐振,功率管直通导致稳定后输出电压等于输入电压的结论。最后给出了解决该问题的电路。实验结果表明,该电路可有效抑制短路恢复过程中的输出电压过冲。
The reason why cycle by cycle current limit can not function even at peak current mode PWM is analyzed.Output overshooting during short circuit recovery of Buck converter in automobile electronic system is discussed.The process of the inductor going into saturation gradually owing to drop voltage of catch diode and trace during output short circuit is also discussed.Spike voltage of output at leading edge is caused by the inductor and output capacitance.Power MOSFET holding always on makes output voltage equal to input voltage.The solution to treat this issue and test results are given in the end.
出处
《电力电子技术》
CSCD
北大核心
2008年第10期39-40,共2页
Power Electronics
