基于信号功率谱的模拟电路嵌入式测试

针对模拟电路内建自测试问题,提出一种基于信号功率谱的嵌入式测试方法.采用由电压比较器构成的采样器对被测电路的输入信号和输出信号进行采样,得到频谱特性不变的数字信号序列,使用最大熵谱法计算输出序列和输入序列之间的功率谱密度比,将得到的比值与正常电路的比值进行分类比较后,确定被测电路的故障状态.在基于DSP的模拟电路测试平台上,应用信号功率谱方法对低通滤波器电路进行测试.结果表明:该方法能有效地检测模拟电路中的各种故障,硬件实现方案简单易行,适合模拟电路的嵌入式测试.

Analogue circuit embedded test based on signal power spectrum

In order to do self-testing within analogue circuit,an embedded test method based on signal power spectrum is proposed.Both the input and output signals of the circuit under test are sampled using a sampler which consists of a voltage comparator.As a result two digital signal series are obtained.The power spectrum density ratio between output series and input series is then computed using maximum entropy spectrum estimation algorithm.The ratio value is compared with that of fault-free circuit to identify the circuit faulty status.A filter circuit is tested on a DSP analogue circuit test platform to verify the method.The result shows that the method can effectively detect the faults in the circuit,and the hardware construction is simple.Therefore,it is applicable for embedded test.