宽温工作的HCNR201隔离式调理电路设计

HCNR201 conditioning circuit with isolation for wide temperature working

基于典型的HCNR201隔离电路参考设计,设计了一种支持双极性信号和交流信号有效值测量的隔离式调理电路,分析了调理通道电路组成,剖析了HCNR201的隔离电路工作原理,从理论上对隔离前后设计电路参数选择作了分析,可为不同电压范围的信号隔离电路设计提供设计依据。同时,分析了参考电路中二级管的高温反向电流对隔离输出精度的影响,对隔离电路作了高温＋60℃工作性能测试,确认了调理精度能从常温的0.1%下降到1%以下。从原理上推导和确认了二极管1N4148反向电流对隔离输出精度的影响,实现了隔离电路改进设计,提高了HCNR201隔离式调理通道的宽温工作精度和适用性。

Based on the typical HCNR201 isolation circuit reference design,conditioning circuit with isolation for bipolar analog signal and AC signal rms measurement was designed.The composition of conditioning channel circuit was provided,and the working principle of HCNR201 isolation circuit is analyzed.the selection mechanism of circuit design parameter in the front and rear circuits was realized.It can provide design basis for signal isolation circuit design for different voltage range.The working test at＋60 ℃ was made with application of the diode 1 N4148 in conventional isolation circuit,and It is detected that the conditioning accuracy can be reduced from 0.1% at room temperature to below 1% at＋60 ℃.The effect of the diode 1 N4148 reverse current on the isolated output accuracy was confirmed by the woking principle,and an improved isolation circuit wasprovided,which ensured accuracy of the HCNR201 isolation conditioning channel in wide working temperature.