The Engineering Life--Around the Web
It's all about the coulombs now. Some products run for years off a single coin cell and any excess electron use will drain that power source prematurely.
If you're building low-power electronics, it's important to be able to measure current consumption, sometimes to very low values. Few digital multimeters (DMMs) can measure much sub-1 µA. My Extech 330, for instance, has a 0.1-µA digit but is unsurprisingly inaccurate when presented with a couple of hundreds of nA (nanoamp).
A nA isn't much, but some controllers today claim sleep currents of just tens of nA.
One nifty tool is the µCurrent from EEVblog's Dave Jones. It's a very simple circuit adapter consisting of not much more than a selectable set of shunt resistors and an op amp. You could cobble up your own design in no time, but the µCurrent is inexpensive and well-engineered.
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