一种中大功率多路低噪声开关电源的设计

A Medium and High Power Switching Power Supply Design with Low Noise Multiple Outputs

高精密电子系统对开关电源的低噪声要求日趋普遍,需求功率也日益增大。针对开关电源的噪声来源与特点,综合利用多重噪声抑制措施方有可能实现低输出噪声。着重介绍了一种多路输出开关电源的低噪声设计思路,从基础变换电路的低噪声设计和外围电路的低噪声处理方面进行了分析,对开关管、整流管、变压器辐射、布局布线与引出线处理、共模噪声抑制等采取对应噪声抑制方法。最后运用该方案试制了一款实际电路,通过实测表明设计满足预期要求。

The low-noise requirement of switching power supply(SPS)is becoming more and more common,and the power demand is also growing in high-precision electronic systems.According to the noise source and its characteristics of SPS,it is possible to achieve the output of low noise by comprehensive utilization of multiple noise suppression measures.In this paper,a low-noise design of SPS with multiple outputs is introduced emphatically,and the low-noise design of fundamental converter and its peripheral circuit is analyzed.Then,the noise suppression scheme in regard of switching transistor,rectifier,transformer radiation,layout,wiring,outgoing line and common-mode noise is adopted.Finally,a practical circuit is trial-produced by using the scheme,and the results show that the design has met the expected requirements.