电源瞬态电流信号高精度测试电路设计与仿真验证

Design and Simulation Verification of A High-precision Power Supply Transient Current Signal Extraction Circuit

电源瞬态电流测试(IDDT)是一种对电路传统测试方法的新的补充手段,对电路故障诊断具有重要意义。由于电源瞬态电流信号本身具有高速、短暂、易被噪声干扰等特性,使得IDDT信号难以捕捉。提出一种以三运放仪表放大结构为主体,能有效克服射频干扰,同时具有轨到轨输出能力的高性能IDDT片外电流检测传感器电路设计。用Pspice仿真捕捉到Sallen-key滤波器电路50us的动态电源电流信号波形,仿真结果表明设计的传感器电路能够有效读取待测的Sallen-key滤波器电路不同故障模式下的IDDT波形,为利用电源瞬态电流测试提供了一种有效手段。

Power supply transient current test（IDDT）is a new supplementary means of traditional circuit test methods with great significance.Since the power supply transient current signal itself has the characteristics of high-speed,short-lived and susceptible to noise,etc.,making it difficult to capture IDDT signal.A three-op-amp instrumentation amp is proposed as the main structure which can overcome RF interference while having rail to rail output capability,high-performance offchip IDDT current sensor.With Pspice simulation to capture the dynamic supply current waveform Sallen-key filter circuit50μs simulation results show that the design of the sensor circuit can effectively read IDDT waveform under different failure modes,enabling power supply transient current test.