Just a pretty basic electronics question here. I’m making a Teensy based musical synthesizer project which has a USB Host board attached to it so I can plug in USB keyboards into the synthesizer. These keyboards will be powered by the USB Host board (SAM21 Seeduino XIAO with the Arduino USB SAMD Host Library), which is powered from the Teensy, which is powered either via USB 5V or a 5V power adapter.
Apparently, plugging in a USB Device can cause a quick current spike which could restart the Teensy, so it’s advised to add in a 120uF capacitor near the power line. My question is pretty basic: does it matter where along the power line I place the 120uF capacitor? Should I put it in front of the USB Host Board 5V input, or the Teensy VIN? Or both, or does it matter? Just want to get everything right before I get a PCB printed. Thank you!
I’ve attached a couple of photos of my schematic/