Asynchronous Time-domain Amperometric Sensor Interface For a Wide Range of Cdl

The linearity and stability of an amperometric sensor can be affected by the size of the double layer capacitor (C-dl) in the electrode. A working electrode (WE) with millimetre size area can have a C-dl larger than 10nF, whereas a WE in nanometer range show tens of femto-Farad C-dl. We propose an amperometric sensors that is immune to the negative effect introduced by a wide variance of C-dl, but does not require and additional mismatch calibration. By using dynamic current mirrors, the resolution of the sensor is increased to over 9bits. We perform extensive simulation to determine linearity (R-2 > 0. 999), DNL and noise floor all within acceptable limits.

Automated summary

The paper introduces an amperometric sensor that is immune to variations in double layer capacitor size and does not require additional calibration. By using dynamic current mirrors, the sensor's resolution is increased to over 9 bits. Through extensive simulations, the linearity, DNL, and noise floor of the sensor are all within acceptable limits.