A 19 μW, 50 kS/s, 0.008-400 V/s Cyclic Voltammetry Readout Interface With a Current Feedback Loop and On-Chip Pattern...

Area of Science:

• Electrochemistry
• Integrated Circuits
• Sensor Technology

Background:

• Electrochemical sensing requires precise current detection over a wide dynamic range.
• Existing potentiostat designs often face limitations in linearity and noise performance.
• High-speed and accurate signal generation is crucial for advanced electrochemical techniques.

Purpose of the Study:

• To develop a novel cyclic voltammetry electrochemical sensing chip with enhanced current detection capabilities.
• To improve linearity, accuracy, and conversion rates for electrochemical measurements.
• To enable versatile measurements across a broad range of scan rates.

Main Methods:

• Implementation of a time-based readout circuit with a current feedback control loop.
• Utilization of a chopper-stabilized, low-noise potentiostat and a delay chain time-to-digital converter.
• Integration of an on-chip pattern generator with a current reducer for multi-rate ramp signals.

Main Results:

• Achieved an 8-nA current resolution within a -7 μA to 10 μA range with R² linearity of 0.999.
• Demonstrated low power consumption (19 μW) and a low Allan deviation floor (4.83 Hz).
• Obtained a limit of detection of 31 pM for K₃[Fe(CN)₆] and supported scan rates from 0.008 V/s to 400 V/s.

Conclusions:

• The developed chip offers a high-performance solution for electrochemical sensing with wide-range, high-linearity current detection.
• The design effectively mitigates nonlinearity and noise, enhancing measurement accuracy and sensitivity.
• The versatile scan rate capability and low power consumption make it suitable for various electrochemical applications.