Hello!
I recently made a circuitboard that utilizes an Artemis module and a DC-DC buck converter for an always on 3.3v
I think I made the layout incorrect for my 3.3v converter because it fluctuates up to 3.6v and then drops below 1v sometimes. All the other complicated IC’s of my board work great, even my own 180v power supply design. Of course, it’s the relatively simple thing that didn’t work (grr).
I recently realized they make high efficiency LDO’s with low quiescent currents. That would have simplified things greatly… What is your opinion on an application that needs 10’s of uA at idle (running the RTC on the Artemis module), and then maybe 50mA when fully operating? Would you use a DC-DC buck converter or an LDO?
given a Vin of 5v-8.4v
Thanks! Just trying to learn
LDO’s are my personal go-to’s, but they can have limitations. Most of the LDO’s used on SFE products generally have 6V max for input voltage. The LDO’s will keep a more level operating voltage compared to DC-DC buck converters that can depend largely on the input voltage. I would suggest researching more into the specifics of the DC-DC buck that you’re using/designing. Also check out some of our schematics and designs using LDO voltage regulators.
Hi Brandon,
I opted to change out the buck converter (TPS6217x) for this LDO, TPS7B81-Q1
It has a nice input voltage of up to 40v with a quiescent of around 2.7uA. I don’t plan on drawing much current from it, and even if I do, I don’t mind the level of energy lost in this part of the device I’m trying to make.
In the meantime, I cut out my failed switching regulator and tapped off the FT232x internal 3v3 regulator to let me start to try and code things up 
At least the 180v power supply part of the circuit worked! Few…
Glad to hear it, keep up the good work! 