Abstract: Using an IC (MAX971) that includes an open-drain comparator and a precision 1% voltage reference, this circuit monitors the magnitude of a negative supply voltage and provides a digital warning of fault conditions. To monitor multiple negative voltages, use the MAX974, which includes four comparators. Maxim > App Notes > Amplifier and Comparator Circuits Microprocessor Supervisor Circuits Voltage References Keywords: negative supply voltage, multi-rail systems, comparators, voltage references Dec 07, 2010 APPLICATION NOTE 4543 Precision Circuit Monitors Negative-Supply Thresholds By:Kevin Bilke Abstract:Using an IC (MAX971) that includes an open-drain comparator and a precision 1% voltage reference, this circuit monitors the magnitude of a negative supply voltage and provides a digital warning of fault conditions. To monitor multiple negative voltages, use the MAX974, which includes four comparators. A similar version of this article appeared in the February 8, 2008 issue of Portable Design magazine. A simple but ac……