I need to amplify a differential signal and control the gain with a microcontroller. Both the positive and the negative input signal are between 0 to 5V to ground... Voltage gain should be between 1 (or less) and maximum gain at least 100 times. It's not required to control the gain in precise steps ("scope" gains of 1,2,5... or binary 1,2,8, or even decimal 1,10,100,1000 is ok). The output is single-ended. If possible, i want to supply the amp with +5V and -5V, so rail to rail capability on the input and output is required in that case. The gain-bandwith product is also important and should be at least 1MHz.
I searched the hole day to find a solution for my problem. I have searched on the websites of Linear, TI, Analog, Maxim, and I have read several datasheets, but didn't find a solution for my problem...
Many instrumentation amplifiers have a gain that can be set with a single resistor. The gain is than G = 1 + R1/R2, where R1 is an internal resistor. As a result the gain is always more than one...
Maybe there's someone here who had a similar problem and know how to solve this?