Analyte sensor with impedance determination

A continuous analyte sensor comprising:

• an analyte sensor;
• and
• sensor electronics operatively coupled to the analyte sensor to receive a signal indicative of glucose concentration from the analyte sensor, the sensor electronics comprising a measurement circuit;
• and
• wherein the sensor electronics disconnects the measurement circuit from the analyte sensor and reconnects the analyte sensor to the measurement circuit after an accumulation period, and the measurement circuit measures an accumulated charge from the analyte sensor after reconnection of the analyte sensor to the measurement circuit.

A method comprising:

• applying a biphasic pulse to a continuous analyte sensor circuit;
• integrating a current response to the biphasic pulse;
• and
• determining an estimated impedance using the integrated current response.