Diagnostic waveform generator for a sensor

A method for controlling an electrochemical sensor, the method comprising:

• receiving a supply voltage at a control circuit;
• in a diagnostic mode of operation, generating a sensor diagnostic signal at the control circuit using the supply voltage, wherein the sensor diagnostic signal is a periodic signal;
• in a sensing mode, receiving a signal from a working electrode of the electrochemical sensor at the control circuit;
• provide an indication of a material concentration at an output of the control circuit using the signal;
• and
• wherein a peak-to-peak voltage of the sensor diagnostic signal is greater than the supply voltage.

A control circuit for an electrochemical sensor, the control circuit comprising:

• power supply inputs configured to receive a supply voltage;
• means for receiving control information;
• means for applying a first waveform to a reference electrode of the electrochemical sensor during a diagnostic mode of operation using the supply voltage and the control information;
• means for applying a second waveform to a diagnostic electrode of the electrochemical sensor during a diagnostic mode of operation using the supply voltage and the control information;
• means for receiving sense information from the electrochemical sensor;
• means for providing an indication of a material concentration using the sense information during a sense mode of operation;
• and
• wherein, during the diagnostic mode of operation, a diagnostic waveform measured at the reference electrode and the diagnostic electrode includes a periodic signal having a peak-to-peak voltage greater than the supply voltage.