openrcforums

I'm trying to figure out how to get a micro brain flybarless gyro to run off of 1s. Currently, the micro brain used a Micro 5209 LDO regulator that requires +1v above output (3.3v out, so min 4.3vin). Here is the datasheet

The application uses 1s lipo which will drain to about 3.3v under load. No, I can't use 2s and weight is a major consideration.
I was thinking about a joule thief, but have never used one and wasn't sure if it would be suitable for such a sensitive electronic (gyro and frsky rx). I had thought about replacing the regulator with an even lower LDO, but have no idea how to find one (I tried using digikey but lack the knowledge necessary to parse through the inventory/search results)

What would you recommend?

The site won't let me attach the picture/file

I don't know how much current your setup will drain but you might want to check the LP2981 (100mA max) and the LP2985 (150mA max).. They are very low dropout voltage..
You can't expect to discharge the LiPo battery until it reaches 3.3V with any regulator. Even the very low dropout regulators need some voltage at the input above the output voltage.
The dropout voltage also increases with the load..

João

How about a tiny step-up to get the 5V back?
https://www.pololu.com/product/2564

Kilrah, I think he needs 3.3V, not 5V?
Or do you mean, step-up converter to 5V and then an Low dropout regulator to get stable 3.3V?

João

I mean step up to 5V so the device works as it's designed to without modifying it.

I was really hoping for a super ultra mega lower dropout regulator, but it looks like a stepup will have to be the solution.

Thanks, y'all!