I’ve been testing several power supplies for the zynthian and i’ve found this one that gives quite good results. This is the power supply:
And the features from the datasheet:
CE ROHS FCC
Short Circuit Protection, ovp, OTP, OLP, ocp, Low Tension, Over-charging, Overcurrent, Overvoltage
CDQQCM QC3.0 fast phone charger
3.6V-6.5V/3A, 9V/1.67A, 12V/1.5A, 6V 3A/9V 2A/12V 1.5A
AC 100~240V 50/60HZ 0.35A
These are screenshots of the output voltage measured with an oscilloscope at different loads (without cable):
As you can see, it maintain a good behaviour until 2.5 A, dropping when drove over this current level.
I’ve not tested with the official RBPi 4 power supply because i’ve to cut the cable for testing it, but i think finally will do for having a good reference. Anyway, i suspect that it can’t be a lot better than this one.
I’ve also selected a nice cable with a low-enough resistance (1m long, ~0.2 Ohm each conductor) and tested both on my zynthian at very high CPU loads, with 2 keyboards + SQ1 step-sequencer, and the current never reached 2A, while the system remained completely stable, with voltage over 5V all the time.
What do you think? I would like to ear your opinions before buying a batch of these toys …