Jump to content
Sign in to follow this  
cde

Running straight off Battery vs LDO

Recommended Posts

Found a nice app note by TI, and wrote some thoughts on it:
 
Just recently read an app note that targets your same circumstances. Using power solutions to extend battery life in MSP430 applications By TI's Michael Day. While it uses the MSP430 as its target, the same applies to any MCU.
 
Depending on the MCU's Current vs Voltage, and Voltage vs Clock Speed, using an LDO with a low Quiescent Current will be much better than powering the MCU directly off the battery. The example uses 2x AA, and a TPS780xx regulator with 0.5

Share this post


Link to post
Share on other sites

That is a good idea, I recall TI mentioning this app note on twitter a while back. Of course remember the FET... the professional MSP-FET has pins to drive the level shifter to support low voltage use but a LaunchPad might be different.

Share this post


Link to post
Share on other sites

Interesting read.

 

I have a FR6989 launchpad running the default program in temp mode, powered by a 3.6V NiCD cordless phone pack that was charged to about 2.6V. It was connected to the 3v3/GND pins at the lower right of the LP for a few days, then removed for a day so the V would settle, and the jumpers from the ICDI were removed so it didn't power those when running. It has been running continuously since 8am Feb 18, so that's about 8 days / 192 hours on the pack as of 8am this morning, or about 200 hours as of this moment.

 

No doubt a few, cheap solar panels would extend the run time by at least an order of magnitude... as would modifying the stock code to take advantage of the processor's low power abilities.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...