Power-miserly voltage reference needs just one pin

摘要

The supply rail normally powers a microcontroller's voltage-reference source. In power-critical battery-operated applications, the constant drain, even of a few 10s of micro-amps, can be prohibitive. This situation requires adding a pin to turn the reference voltage on and off. By adding a 0.1-μF capacitor in parallel with the voltage reference and a simple bit of software that you can download from the online version of this Design Idea at www.edn.com/090820dia, you'll need just one pin to both power and read the reference voltage.