Sensing small currents in battery-powered projects

[Alan]

You’re working with a delicate little circuit, trying to avoid any mishaps while you measure those minuscule currents. Should you go for a shunt or a Hall effect sensor? And which op-amp really gets the job done? I’d love to hear your tricks, tips, and layout hacks that actually make a difference.

 

[Tovaren]

For a battery monitoring project, I tested both options. The Hall sensor was easy to work with but kept drifting with temperature changes. On the other hand, the shunt along with a chopper-stabilized op-amp gave me consistent results. My biggest breakthrough was protecting the traces and ensuring digital noise stayed far away.

 

[cap&resistor]

I initially went with a Hall sensor for isolation, but after weeks of battling noise, I switched back to a precision shunt paired with a low offset op-amp.
With a tight layout, Kelvin connections, and slow averaging, I managed to keep my sanity intact better than anything else.

 

[theOhmcoder]

The first time I tried to measure tiny currents, I accidentally fried a shunt just by sneezing close to it.
Since then, I’ve found that using a low-value shunt along with a solid instrumentation amplifier does the trick.
I’ve learned that proper grounding and short traces are way more important than having fancy components.