I have a reference design circuit with 4 power rails. Already designed into the circuit are 4 high side current sense shunt resistors. What's the best way I can continuously measure the voltage across each of these shunts simultaneously? I already have a multi-channel scope, but the inputs share GND. The circuit to be measured is a low voltage, low current circuit (<5V, 1mA to 1A with 500uA resolution).
Is there some off-the-shelf multi-channel amplifier system that i can buy and plug into my scope inputs? I'm looking to avoid having to do any circuit design or soldering for the measurement system.
Edit: (1) The voltage rails are at 5V, 3.3V, 1.8V, & 1.2V (2) Sampling rate is >=20KHz