ION-SENSING CHARGE-ACCUMULATION CIRCUITS AND METHODS
First Claim
1. An ion-sensitive circuit, comprising:
- a charge-accumulation device to accumulate a plurality of charge packets as a function of an ion concentration of a fluid, including;
a first charge control electrode, above a first electrode semiconductor region, to control entry of charge into a gate semiconductor region in response to a first control signal applied to the first electrode; and
an electrically floating gate structure above a gate semiconductor region and below an ion-sensitive passivation surface configured to receive the fluid;
a second charge control electrode, above a second electrode semiconductor region, to control transmission of the plurality of charge packets out of the gate semiconductor region and into a drain diffusion region in response to a second control signal applied to the second electrode; and
a drain diffusion region to receive the plurality of charge packets from the gate semiconductor region via the second electrode semiconductor region,at least one control and readout transistor to generate an output voltage as a function of the accumulated plurality of charge packets at the drain diffusion region of the charge accumulation device, wherein the output voltage is representative of the ion concentration of the solution.
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Accused Products
Abstract
An ion-sensitive circuit can include a charge accumulation device, to accumulate a plurality of charge packets as a function of an ion concentration of a fluid, and at least one control and readout transistor, to generate an output signal as a function of the accumulated plurality of charge packets, the output signal representing the ion concentration of the solution. The charge accumulation device can include a first charge control electrode above a first electrode semiconductor region, an electrically floating gate structure above a gate semiconductor region and below an ion-sensitive passivation surface, a second charge control electrode above a second electrode semiconductor region, and a drain diffusion region. The first control electrode can control entry of charge into a gate semiconductor region in response to a first control signal. The ion-sensitive passivation surface can be configured to receive the fluid. The second charge control electrode can control transmission of the plurality of charge packets out of the gate semiconductor region and into the drain diffusion region in response to a second control signal. The drain diffusion region can receive the plurality of charge packets from the gate semiconductor region via the second electrode semiconductor region.
165 Citations
19 Claims
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1. An ion-sensitive circuit, comprising:
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a charge-accumulation device to accumulate a plurality of charge packets as a function of an ion concentration of a fluid, including; a first charge control electrode, above a first electrode semiconductor region, to control entry of charge into a gate semiconductor region in response to a first control signal applied to the first electrode; and an electrically floating gate structure above a gate semiconductor region and below an ion-sensitive passivation surface configured to receive the fluid; a second charge control electrode, above a second electrode semiconductor region, to control transmission of the plurality of charge packets out of the gate semiconductor region and into a drain diffusion region in response to a second control signal applied to the second electrode; and a drain diffusion region to receive the plurality of charge packets from the gate semiconductor region via the second electrode semiconductor region, at least one control and readout transistor to generate an output voltage as a function of the accumulated plurality of charge packets at the drain diffusion region of the charge accumulation device, wherein the output voltage is representative of the ion concentration of the solution. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method of detecting an ion concentration of a fluid, comprising:
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passing the fluid having the ion concentration over an ion-sensitive passivation surface above a gate structure of a charge accumulation device of an ion sensitive circuit; individually forming, one at a time, a plurality of charge packets in a gate semiconductor region of the charge accumulation device below the gate structure as a function of the ion concentration in the fluid; applying a control signal to a control electrode above an electrode semiconductor region of the charge accumulation device to control transmission of the charge packets one at a time from the gate semiconductor region; accumulating the plurality of charge packets at a drain diffusion region of the charge accumulation device at a selectable charge packet accumulation frequency; and generating an output signal using at least one control and readout transistor as a function of the accumulated plurality of charge packets at the drain region at a selectable output signal generation frequency, wherein the output signal represents a measure of the ion concentration in the fluid. - View Dependent Claims (16, 17, 18, 19)
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Specification