I am working on a device to measure the current of a supply in real time. The purpose of this, is to help with software development of ultra-low power 'always on' devices to be more efficient. The biggest market for this currently is IoT.
I want to have both speed and accuracy from an amplifier and I have therefore discarded all of the purpose made current sense amplifiers as they don't provide sufficient bandwidth for my application.
The specifications required are as follows:
I have been looking at the AD8220 for a rail to rail inamp, or the AD8221 which appears to be a better device for me, but will require a dual supply to get the full swing.
Can anyone suggest any better suited iamps that I have missed, or do these 2 seem the best suited for this application?
Any support will be very much appreciated.
Many Thanks Ian.
Muxes like the ADG1407 have to use larger devices to get the low R_on. Therefore they end up with higher capacitance. In-amps like the AD8253 or AD8221 have very high input resistance, so the on-resistance of the mux in series with the in-amp input doesn't introduce much error. In cases like this you can usually get better performance from a low capacitance mux like the ADG1207 instead. Other than that, it all seems quite reasonable to me.