Hello,
I’m doing measurements and tests on my V3 such as battery life, minimum voltage, current draw, and such. The tests are going great and I like the results, but being a circuit designer, myself, I am very curious about the device labeled overvoltage protection. The part number is not shown, but the .brd file on GitHub implies is it a NX1117C15Z, which, being a 1.5V linear regulator can’t be right, except perhaps for the same footprint as the actual device. If it a 5V version of the same device type, then that is an usual use case for that particular device, for sure, operating just fine at an input voltage less than its output voltage. So, my primary question what is the actual part number for U3? Thanks!
On the Pixelblaze V2 schematic, that same chip U3 is labeled LDL1117S50R. The 1117 family is an LDO regulator available in several fixed output voltages, and that’s the 5.0V version. I assume it’s there to protect against a voltage higher than 5V being fed into the board.
Thanks folks! Wow, I wouldn’t have expected it, but my PB V3 works down to 3.35 V injected at the USB port and maybe even lower. That was the lowest I tested it because the sensor board started giving me noisy freq magnitude data probably due to poor regulation of power at that input voltage and resulting audio noise and that’s the limit for my uses. Who woulda thought that a 5V regulator passes 3.3 volts like it was nothing? Well, it does! Am I just lucky? I’ll take it.
Yep, it’s super handy for running LEDs and Pixelblaze right from a lipo.