Voltage detector monitors power supplies in computers and digital systems

Designed to support the supervisory circuits of microprocessors and microcontrollers, the APX803L micro-power voltage detector from by Diodes Incorporated allows accurate monitoring of voltage levels and will generate a reset signal whenever a supply rail falls below a defined threshold. This function is required by many systems, including computers and communications equipment, but particularly portable battery-powered devices. The device’s low quiescent current also makes it very attractive when appliances like televisions are operating in standby mode. Offered in a detection voltage level range of 1.2V to 5V in 0.1V steps, the device provides a threshold accuracy of ±1.5%, while consuming just 1µA and requiring no external components. Whenever the monitored VCC power supply rail drops below the chosen threshold, the device asserts a reset signal within 20µs that is held until the supply rail recovers to a level above the threshold. The device’s reset pin provides an open-drain, active-low output with device ordering options that allow for delay times of 0ms, 55ms, 220ms, or 450ms.