Accurate and Precise Negative Adjustable Voltage Range

[ecaits]

In potentiostat ( Three Electrode System) of electro-chemical, I need to apply negative voltage range from -1.50 to -0.30 DC V (up to 50 mA range) as a source power to electrodes, and that the negative voltage source must be very precise and accurate.

I am also thinking about PIC or Arduino microcontroller, if I can do on it..

Please suggest for circuit and/or microcontroller....

 

[Mikebits]

Most EC sensors that I have worked with have a fixed voltage for the reference terminal. For example the sensor I used needed a fixed 600 mV reference. Have a look at this app note for EC sensors. Also keep in mind, for many of the sensors that need a negative bias. The following is from the app note referenced below:

Figure 3 shows a potentiostat circuit for a biased sensor.
This circuit is designed to provide a bias of +300 mV
between the sense and reference electrodes by using a
300 mV VSET supply.
Operational amplifier IC1 monitors the potential of the
reference electrode, VREF and applies an appropriate
potential VCOUNT to the counter electrode to keep VREF
equal to VSET (300 mV).
The potential of the sensing electrode is held at 0 V by the
biasing effect of the output circuit so the result is a +300
mV bias between VSENSE and VREF.
This +300 mV biasing arrangement is suitable for NO and
ETO sensors. For oxygen sensors which require a 600
mV bias between VSENSE and VREF it is necessary to use
VSET = +600 mV. In this case the VSET supply would be
connected between +V and ground.
WARNING: Applying an incorrect bias voltage may
damage the sensor.

https://www.sgxsensortech.com/conte...2-Design-of-Electronics-for-EC-Sensors-V3.pdf

Also, for the 600mV reference I used this part made by On Semi: https://www.onsemi.com/pub/Collateral/CAT102-D.PDF