Microcontrollers (MCU)

Design Support

Getting Started

Selection Tool

Training & Events

Developer Network

University

 979 views

Often in applications with keypads, the condition can occur where a key can be held or stuck down, causing excess current consmption and reducing the battery life of a battery-operated product. This application report shows a solution. The keypad interface in this report, based on the MSP430, draws .1uA while waiting for a key press, is completely interrupt driven requring no polling, and consumes a maximum of only 2uA at 3V if all keys are pressed and held simutaneously.