Low Cost, Level Shifted Low Side Current Monitor for Negative High Voltage Rails

The measurement result from the AD7171 is provided as a digital code utilizing a simple 2-wire, SPI-compatible serial interface. The entire circuit operates on a single +3.3 V supply. Optional galvanic isolation is provided by the ADuM5402 quad channel isolator. In addition to isolating the output data, the ADuM5402 digital isolator can also supply isolated +3.3 V for the circuit. The ADuM5402 is not required for normal circuit operation unless galvanic isolation is needed.

This combination of parts provides a accurate high voltage negative rail current sense solution with a small component count, low cost, and low power. The accuracy of the measurement is primarily determined by resistor tolerances and the accuracy of the band gap reference, and is typically better than 1.

AD7171属于集成电路（IC） > 模数转换器（ADC）。亚德诺半导体技术有限公司制造生产的AD7171模数转换器（ADC）模数转换器（ADC、A/D 或 A 转 D）对模拟信号进行采样，例如由麦克风采集的声音或传感器的输出，然后将其转换为数字信号。一般来说，数字输出是二进制补码二进制数，与输入成比例。输入类型可能是差分、伪差分或单端输入。模数转换器可按照位数、采样率、输入数、接口、转换器数和架构（例如自适应增量、双斜率、折叠、流水线、SAR、三角积分、两步式）进行选择。