How to use brownout ?

karti.m · Joined: 07 Jul 2011 Posts: 5

Can anyone explain what is brownout and how to use it?

asmboy · Joined: 20 Nov 2007 Posts: 2128 Location: albany ny

the DATA sheet for the pic explains it....
when the dc voltage falls below the brownout point - the pic shuts off and resets itself only after the supply voltage exceeds the brownout voltage set by default or fuses

ezflyr · Joined: 25 Oct 2010 Posts: 1019 Location: Tewksbury, MA

Hi,

And, I'll add that 'brownout' detection is useful to ensure an orderly shutdown of your PIC when the power source goes away. The idea is that the PIC is still operating "normally" at the brownout trip point, and resets cleanly at this point before the voltage falls any lower and the PIC (potentially) starts to act erratically (I/O changes, etc.).

I had a project recently that was interpreting a falling supply voltage as a switch closure (switches are wired to pull an input to Gnd when pressed), and that was triggering some unintended EEPROM writes. The problem was totally solved by enabling brownout detection.

John