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.
Have you looked at the AD8130? it's intended as a differential line receiver, but is very fast ( a faster variant of the AD8420 mentioned above). It uses indirect current feedback, so for example you can refer the output signal to mid supply for bipolar input to a differential ADC. It only uses a single gain resistor, so it is possible to change the gain without the CMRR issues. and it works nearly rail to rail, so no issues with the "hexagon".