Creating a 64kHz current signal with a DAQ?

[Adamgot]

I am going to do some impedance measurements and need a device to generate a 64kHz low current(0,1mA) signal, and to pick up 2 differential voltages. Is there any multifunction DAQ devices that outputs a constant current or can i use a device with a voltage output and use a voltage to current converter? 

Adam

[Henrik_Volkers · Accepted solution]

I'm not aware of a metrologic current source for 100µA @ 64kHz ..

I would try this:

http://www.edn.com/design/analog/4324499/Bipolar-current-source-maintains-high-output-impedance-at-h...

Why not just apply a AC voltage and measure current and voltage(s) ?

Another way to apply a 100µA rectangular waveform: Place a REF200 (2 100µA references) in a diode bridge and apply a 64kHz squarewave 🙂

[Henrik_Volkers]

And can you tell me which suggestion you choosed?