模拟乘法器零漂抑制技术

Analysis of zero-drift suppression by analog multiplier

为克服现有调零技术的不足,分析了模拟乘法器零漂产生的原因,建立了乘法器的等效模型,提出了一种高精度的模拟乘法器零漂补偿电路;采用传输线变压器技术、低阻调零技术、温度补偿技术和数字调零技术提高零漂抑制效果,对零漂补偿电路参数提取方法进行了研究。实验结果表明:采用综合补偿技术后,可以将模拟乘法器的原始零漂降低3个数量级。

The cause of zero-drift led to the establishment of the model of analog multiplier was ana~ lyzed. A high-precision zero-drift compensating circuit was proposed, which is better for the analog multiplier. A transmission line was introduced into the input port to reduce the effect of bias current. The impedance between Z and ground was minimized so as to suppress the bias current; Furthermore, the compensating circuit for temperature and the digital controlled potentiometer were used to improve the reliability. Also, an investigation was conducted into the ways to extract the parameters of the zero-drift compensating circuit. The experimental results show that the original zero-driftis reduced by three orders of magnitude by means of the compensating techniques.