Low power current measurement tool

[Wojtek]

I am wondering how to precisely measure my power consumption. Till now, I have been using INA216 on PCA10004 board + labView for acquisition, but it is not precise enough (I can't get measurements lower than about 35microAmps, when i expect slightly smaller power consumption).

Do You guys have some solutions that can be used to measure up to ex. 50miliAmps with 1microAmp precision and doesn't cost few thousands euros? I found device called µCurrent but I am still looking for alternatives. What tools do You use to measure low power devices?

[Øyvind Karlsen]

Hi,

High accuracy µA measuring equipment is expensive. What you are asking for is something which has a very high dynamic range, which is when you have a large span of currents, 50mA to 1µA, you want to measure in one sweep. High dynamic range will jump you up another level of expense.

The cheap solution for you will probably be something like the µCurrent or a medium grade multimeter or ammeter. If you already have a good oscilloscope it might be possible to measure the current by measuring voltage over a 1 ohm resistor.

The trade-off is that you will have to be very careful with your test scenarios. That means that you might want to use a capacitor or coil to smooth out your current spikes to lower the dynamic range. You may even have to do measurements for just a single state(idle, active, etc) at a time and then do maths to get accurate results.

Best regards,

Øyvind