Circuitry for measurement of electrochemical cells

Circuitry for characterising an electrochemical cell, the circuitry comprising:

• measurement circuitry;
• switching circuitry configured to selectively couple the measurement circuitry to respective first and second working electrodes of the electrochemical cell;
• and
• calibration circuitry;
• wherein, in a first mode, the switching circuitry is configured to hold the first and second working electrodes at respective first and second bias voltages and calibration circuitry is configured to calibrate the measurement circuitry,
• wherein, in a second mode, the switching circuitry is configured to hold the first working electrode at the first bias voltage and couple the second working electrode to the measurement circuitry, and the measurement circuitry is configured to measure a second signal at the second working electrode, and
• wherein, in a third mode, the switching circuitry is configured to hold the second working electrode at the second bias voltage and couple the first working electrode to the measurement circuitry, and the measurement circuitry is configured to measure the second signal at the second working electrode.

A method of processing an analyte signal obtained from an electrochemical cell, the method comprising:

• measurement circuitry having a first measurement input coupled to a first electrode of the electrochemical cell, the measurement circuitry configured to convert the analyte signal at a first electrode of the electrochemical cell to a first analog output signal;
• convert the first analog output signal to a first digital output signal;
• in a measurement mode to:
• apply a first compensation to the first digital output signal to obtain a first compensated digital output signal, the first compensation to compensate for non-linearity in the ADC;
• and
• apply a second compensation to the first compensated digital output signal to obtain a second compensated digital output signal, the second compensation to compensate for non-linearity in the measurement circuitry;
• and
• in a calibration mode to:
• apply a first calibration signal to the first analog output signal and adapt the first compensation based on the first calibration signal and the first compensated digital output signal;
• and
• apply a second calibration signal to the first analog output signal and adapt the second compensation based on the second calibration signal and the second compensated digital output signal.