在大功率DC/DC开关电源中,为了获得更大的功率，特别是为了得到大电流时，经常采用N个单元并联的方法。多个单元并联具有高可靠性，并能实现电路模块标准化等优点。然而在并联中遇到的主要问题就是电流不均，特别在加重负载时，会引起较为严重的后果。普通的均流方法是采取独立的PWM控制器的各个模块，通过电流采样反馈到PWM控制器的引脚FB或者引脚COMP，即反馈运放的输入或者输出脚来调节输出电压，从而达到均流的目的。显然，电流采样是一个关键问题：用电阻采样，损耗比较大，电流放大后畸变比较大；用电流传感器成本高；用电流互感器采样不是很方便，同时会使电流失真。本文提出了一种新型的、方便的、无损的电流采样方法，并在这种电流检测方法的基础上实现了并联系统的均流。 -in High Power DC / DC switching power supply, in order to gain more power, in particular in order to obtain the current, frequently using N units parallel method. Parallel number of modules with high reliability, and the circuit module can achieve the advantages of standardization. However, in parallel encountered in the current main problem is uneven, particularly in the heavier load, it will cause more serious consequences. The general flow is to have an independent PWM controller modules, Current sampling through feedback to the PWM controller pin FB pin or COMP. that feedback operational amplifier input or output pin to adjust the output voltage, thereby achieving both flow purposes. Clearly, the current sampling is a key question : sampling resistor, loss comparison, the amplifier dis