DC/low frequency sub-atto signal level measurement circuit
AssigneeUniversity of Waterloo
InventorsArokia Nathan, Yong Lu, Tajinder Manku
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Abstract
A method of measuring changes in signal level output of an integrated circuit sensor by providing a direct current (DC) or low frequency (AC) bias to the sensor and placing a floating gate semiconductor device on-chip and coupling the floating gate of the semiconductor device with the sensor. As a result, changes in signal level output of the sensor modulate charge at the gate. The semiconductor device in turn converts the modulated charge at the gate into output signals proportional to the changes in the signal level output. The measurement method provides a resolution in the sub-atto range.
Claims18
A method of measuring sensor output using an integrated circuit sensor device including an on-chip integrated circuit sensor and a separate on-chip integrated circuit semiconductor device, said method comprising the steps of:
- providing a direct current (DC) or low frequency (AC) bias to said sensor;
- and
- tightly coupling a floating gate of said on-chip semiconductor device to said on-chip sensor so that changes in signal level output of said sensor modulate charge at said floating gate, said semiconductor device converting modulated charge at said floating gate into output signals proportional to the changes in said signal level output of said sensor.
A signal measurement method of generating output proportional to a change in signal level output of an integrated-circuit sensor using a floating gate integrated circuit semiconductor device, said method comprising the steps of:
- fabricating an integrated circuit including said integrated circuit sensor and said floating gate semiconductor device, said integrated circuit sensor and said floating gate semiconductor device being separate, tightly coupled components;
- DC or low frequency AC biasing said integrated circuit sensor;
- applying the signal level output of said integrated circuit sensor to a gate of said floating gate semiconductor device so that a change in the signal level output modulates gate charge;
- and
- converting the modulated gate charge into an output signal proportional to the change in said signal level output.
An integrated circuit sensor device comprising:
- an integrated circuit sensor;
- and
- a floating gate integrated circuit semiconductor device including a drain node, a source node and a gate node, said gate node being coupled directly to said sensor so that a change in the signal level output of said sensor modulates charge at said gate node, said semiconductor device converting the change in charge at said gate node into a drain-source current that appear as a drain-source voltage proportional to the change in said signal level output, wherein said sensor and said semiconductor device are tightly coupled but separate on-chip integrated circuit components and said semiconductor device generates an output signal in response to a change in said signal level output in the sub-atto Farad range.
An on-chip integrated measurement circuit comprising:
- an integrated circuit sensor;
- and
- a FET device including a drain node, a source node and a gate node, said gate node being coupled directly to said sensor so that a change in the signal level output of said sensor modulates charge at said gate node, said FET device converting the change in charge at said gate node into a drain-source current that appear as a drain-source voltage proportional to the change in said signal level output, wherein said sensor and said FET device are tightly coupled but separate on-chip integrated circuit components and the FET device is responsive to a change in said signal level output in the sub-atto Farad range.
Dependencies are inferred from the claim text.