Hi,
I want to measure an impedance of up to 100kOhm (with a capacitive part that should also not exceed j*100kOhm at 100kHz). Maybe I could go down to 1kOhm or 100 ohm, quite a range I know. I'll be doing a 4 point with instrumentation amplifier that I can easily switch the gain (but suffer BW towards 100kHz) The next challenge is that I'm aiming at a battery powered very small and simple device. So single supply is preferable.
I've looked at current source devices like REF200, but these are DC right? I though also about using an opamp and but something about stability of these things driving these kinds of loads makes me nervous.
Any ideas or suggestion would be most welcome!
Cheers!
I want to measure an impedance of up to 100kOhm (with a capacitive part that should also not exceed j*100kOhm at 100kHz). Maybe I could go down to 1kOhm or 100 ohm, quite a range I know. I'll be doing a 4 point with instrumentation amplifier that I can easily switch the gain (but suffer BW towards 100kHz) The next challenge is that I'm aiming at a battery powered very small and simple device. So single supply is preferable.
I've looked at current source devices like REF200, but these are DC right? I though also about using an opamp and but something about stability of these things driving these kinds of loads makes me nervous.
Any ideas or suggestion would be most welcome!
Cheers!