AnsweredAssumed Answered

AD8130 :  Has anyone used this as a current source?  It would seem to be superior to the Howland pump. (The AD8130 has two inputs

Question asked by bobsbots on Aug 14, 2016
Latest reply on Apr 10, 2017 by liubenyuan

I've just spotted the datasheet for this, It would seem an ideal current source, as it has a floating differential high impedance "input" , and another floating high impedance "feedback" , solves the basic problem with the finite impedance of the reference on a conventional Inst Amp (and Diff Amp), and all the issues with the common mode voltage limitations, and resistor tolerances.

It seems to me you could make usable analogs of any of the four types of sources seen in simulators, VCVC CCVS CCCS VCCS with appropriate placement of resistors.

For example fig139 of the data sheet (below) would be a voltage controlled current source, where Rg sets the mA per volt scaling, and "Voffset" is the floating load that is being driven. (Placing a resistor across the input makes a CCCS).

AD8130 fig139.jpg

The only concerns I would have would be the high bandwidth of the AD8130,  and the ominous note on the above figure "This Circuit Works Well if the VOFFSET Source Impedance Is Low. "

Outcomes