LowPowerLab Forum

Hardware support => General topics => Topic started by: gregcope on January 04, 2019, 02:14:53 PM

Title: recommended 3.3v LDO regulator with an enable pin?
Post by: gregcope on January 04, 2019, 02:14:53 PM
Hi,

Need a regulator to power a GPS/GNSS+active antenna which is around 50ma plus.

Can anyone recommend an LDO 3.3v regulator that has an enable pin?  Efficient would be good!

I might make this into an M0 daughter board.
Title: Re: recommended 3.3v LDO regulator with an enable pin?
Post by: Felix on January 04, 2019, 03:02:49 PM
Use this guide to select a part that has True Output Disconnect technology:
http://ww1.microchip.com/downloads/en/DeviceDoc/LDO-Selector-Guide-Treelink-Final-Draft.pdf

MCP1711 for instance.
Title: Re: recommended 3.3v LDO regulator with an enable pin?
Post by: gregcope on January 07, 2019, 10:59:39 AM
Thanks.

Is there an easy place to get an Eagle libary so that I can add that part.

Also ... what SMD capacitors (sizes) do people start with?
Title: Re: recommended 3.3v LDO regulator with an enable pin?
Post by: Felix on January 07, 2019, 02:42:42 PM
I never ever copy someone else's SMD parts. They can sometimes be incorrectly wired and the pads can be the wrong size, then they fail during reflow etc.

I make my own, that said, I would look to see if microchip has a library, or if someone has created a microchip library with that part, or similar parts.
Anyway making a part is really easy and you should learn how to do it.

For caps, it really depends on technology and the actual value. But generally for values up to 4.7uF I recommend 0603. For 10uF/22uF 0805, and above that 1206 and beyond (large values in small packages are a lot more expensive).
Title: Re: recommended 3.3v LDO regulator with an enable pin?
Post by: gregcope on January 08, 2019, 04:04:23 AM
Thanks Felix.  Having looked its does not look too hard to create a lib part.  Just another thing to learn!