February 1, 2010 -- As more electronic devices become battery powered, conserving that power has become paramount. Recently, manufacturers of microcontrollers have added novel ways to control power consumption through various implementations of electronic switches. By removing power from parts of the chip, dramatic power savings are possible. Advances have also been made in voltage supervisory circuits so that they may be used continuously, consuming only tiny amounts of power.

Traditionally, reduced power consumption has been accomplished in applications by putting the MCU into sleep mode. This method has worked fine for many years, but there are several trends that are now converging that make this solution inadequate.

More complexity has been added to MCUs in recent years, along with the use of more advanced, and therefore leaky, process nodes. Combine this with the market need for 10- to 20-year battery-powered products and it becomes apparent that the traditional sleep mode is often no longer adequate. Extreme low power is now needed.

By Jason Tollefson. (Tollefson is with Microchip Technology, Inc.)