Potentiostat/galvanostat with digital interface

Inventors

Chandrasekhar, Prasanna • Chai, Yanjie

Assignees

Ashwin Ushas Corp Inc

Abstract

A potentiostat/galvanostat employs a controller for providing digital control signals to a digital-to-analog converter (DAC) that generates an analog output signal in response to digital control signals. A high current driver produces a high current output in response to the analog output signal from the DAC. A high current monitor monitors the output from the high current driver to produce a feedback signal for the high current driver to control the current produced by the high current driver and to produce an output dependent on the current supplied from the high current driver for monitoring by the controller. A counter electrode contact for a counter electrode is connected with the output of the high current monitor. A working electrode contact for a working electrode is electrically connected with a fixed stable voltage potential to enable electrochemical analysis of material between the counter electrode and the working electrode. A low current driver produces a low current range output in response to an analog output signal from the DAC. A low current monitor monitors the working electrode contact to detect current at the working electrode contact to supply an output dependent on the current detected for monitoring by the controller and for providing a feedback signal to the low current driver in order to control the output of the low current driver to control current between the counter electrode contact and the working electrode contact.

Core Innovation

The invention is an electrochemical instrument that includes a controller for providing digital control signals, and a digital-to-analog converter generating an analog output signal in response to the digital control signals. The analog output signal drives a high current driver to produce a high current range output under control. A high current monitor is electrically connected with the high current driver to produce a current feedback signal for controlling the current produced by the high current driver and to supply an output dependent on the monitored current for monitoring by the controller.

The instrument enables electrochemical analysis between a counter electrode and a working electrode by providing a counter electrode contact and a working electrode contact connectable in electrical communication with a fixed stable voltage potential. The working electrode contact provides a fixed stable voltage potential for enabling electrochemical analysis of material between the counter electrode and the working electrode. The high current monitor includes a first high current range monitoring circuit for monitoring current in a first current range and a second high current monitoring circuit for monitoring current in a second current range.

The controller coordinates feedback by providing a feedback analog multiplexer path that selects feedback from a low-current sensing signal, a high-current range sensing signal, or a buffered reference voltage signal. A reference-electrode buffer provides buffered reference voltage for voltage-mode feedback at the reference electrode contact. Multiple ADC channels digitize the controller-monitoring inputs corresponding to the selected feedback sources and monitor outputs for control and monitoring.

Claims Coverage

The disclosed subject matter is directed to an electrochemical instrument with one independent inventive claim, supported by dependent claims that refine electrode contact/switching architecture, feedback routing, range-specific monitoring, and controller digitization of monitor/buffer outputs. The independent claim includes 1 core driver/monitor feedback architecture plus 2 range-dependent monitoring circuits for first and second high current ranges.

Overall, the claims cover an electrochemical instrument that uses a controller-provided digital control signal to generate an analog output via a DAC, drives a high current driver, and uses a high current monitor to generate a current feedback signal for controlling the high current output. Electrochemical analysis is enabled through counter and working electrode contacts at a fixed stable voltage potential, and the high current monitor implements first and second range-specific current monitoring circuits.

Stated Advantages

Documented Applications

No documented applications found