I'm trying to measure the power consumption of various MCUs(AVRs and STM32). For this measurement, a power supply and oscilloscope will be used. Because I want to plot the power usage vs time just like the following link, it is not possible to use multimeter and pwoermeter. They have bad time resolution and also delay. Thus power supply, oscilloscope and some ammeter will be used.
But in order to get nice accuracy, time resolution, I'd like to ask what kind of way is the best.
First, shunt ammeter seems not to be recommended, because the expected current draw on MCU would be 0~200mA. The way would show large error.
But I don't know which one is better between feedback ammeter and current probe. For time resolution I need 1~10ms and the currents will be in range of 0~100mA. But I have no idea which one would be better.
Any help will be appreciated.
Best Answer
Use a linear regulator and have the ammeter measure the input of the regulator. That way the unit under test still sees a constant voltage. Make sure to put a ceramic cap immediately between the regulator input and its ground.