Patent ID: 7267751

Claim:
A digitally programmable array-based electronic chip for carrying out biological reactions in response to electrical stimuli, comprising: an array of electrode sites, each electrode site including a sample-and-hold circuit coupled to a working electrode; a plurality of switches for selectively coupling the working electrodes to the output of a digital-to-analog converter (DAC); a control logic module coupled to the DAC and the plurality of switches; a measurement circuit comprising one or more electrical output pathways for selectively coupling the array of electrode sites to an analog-to-digital converter (ADC), the ADC coupled to the control logic module; a current measurement circuit, the current measurement circuit comprising a first selectable connection to the sample-and-hold circuit, a series connected resistor and a second selectable connection to the sample-and-hold circuit, the current measurement circuit operating in a current measurement mode when the first and second selectable connections are closed and in a high impedance mode when the first and second selectable connections are open; and an external processor that digitally interfaces with the control logic module, wherein the communication between the control logic and the external processor includes a clock signal, a data in signal, and a data out signal.