The ICL7665 warns microprocessors (µPs) of overvoltage and undervoltage conditions. It draws a typical operating current of only 3µA. The trip points and hysteresis of the two voltage detectors are individually programmed via external resistors to any voltage greater than 1.3V. The ICL7665 will operate from any supply voltage in the 1.6V to 16V range, while monitoring voltages from 1.3V to several hundred volts. The Maxim ICL7665A is an improved version with a 2%-accurate VSET1threshold and guaranteed performance over temperature.The 3µA quiescent current of the ICL7665 makes it ideal for voltage monitoring in battery-powered systems. In both battery- and line-powered systems, the unique combination of a reference, two comparators, and hysteresis outputs reduces the size and component count of many circuits.ApplicationsµP Voltage MonitoringBattery-Backup SwitchingHigh/Low Temperature, Pressure, Voltage AlarmsLow-Battery DetectionOver/Undervoltage ProtectionPower Supply Fault MonitoringPower-Fail and Brownout Detection