Saturday, May 26, 2018

MIC5205 (LB30, KB30) Low noise regulator, increasing voltage output

Yes, made a mistake, ordered a mic5205 low noise regulator 3.0V output model, when I should had ordered the 3.3V version for a project in the "pipeline".

The typical application for the IC is like this:

This particular IC is not absolutely needed on the project but why not testing new devices....I should had read better the IC reference chart when ordered... should had been MIC5205-3.3BM5 instead of MIC5205-3.0BM5, as you can see, after the dash there's the output voltage, as on the data-sheet:

Looking at the internal diagram (fixed output version on top): looks pretty much a "standard" series regulation schematic so there's room for change the output voltage and that can be done the following way:

By inserting a drop voltage from ground, at the IC GND pin, to a new ground it will "force" a "floating" ground at the anode of the 1N4007 diode, being the drop voltage value at the diode the increase in the schematic output. Any diode will work and depending of the forward voltage there will be the matching increase on the output. In my case the output is now 3.5  V from the original 3V, and that is inside the 2.6 to 3.6 V specs for the devices being powered by this IC downstream.

I'm really not a big fan of the SMD format since I don't have all the proper tools to solder them, anyhow since it's getting harder to get IC's in standard DIP format, in the future, will try to get more up-to-date on surface mount.
Here's a size, comparative to a resistor and the soldering iron tip.

I had to solder it with extra solder and then removed the excess with solder wick.  

Have a nice weekend!

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