Method and circuit employing current sensing to read a sensor
First Claim
1. A sensing apparatus, including:
- at least one sensor cell configured to produce a sensor current indicative of a sensed value; and
a readout circuit having an input node coupled to receive the sensor current, wherein the readout circuit also includes;
an output node; and
output voltage generation circuitry between the input node and the output node, wherein the output voltage generation circuitry is configured to generate an output voltage indicative of the sensed value in response to the sensor current while clamping the input node at a potential that is at least substantially fixed.
1 Assignment
0 Petitions
Accused Products
Abstract
A current sensing method and circuit for reading out a sensor cell, and a sensing apparatus comprising an array of sensor cells arranged along column lines and a current sensing readout circuit coupled to each column line. The sensor cell is configured to assert a sensor current indicative of a sensed value. In operation, an input node of the readout circuit is coupled to the sensor cell, typically by a column line of a sensor array that includes the sensor cell. Preferably, to read out the sensor cell, the sensor current flows from the sensor cell to the input node and in response, the readout circuit charges a capacitor to a voltage indicative of the sensed value while clamping the input node at a potential that is at least substantially fixed.
27 Citations
15 Claims
-
1. A sensing apparatus, including:
-
at least one sensor cell configured to produce a sensor current indicative of a sensed value; and a readout circuit having an input node coupled to receive the sensor current, wherein the readout circuit also includes; an output node; and output voltage generation circuitry between the input node and the output node, wherein the output voltage generation circuitry is configured to generate an output voltage indicative of the sensed value in response to the sensor current while clamping the input node at a potential that is at least substantially fixed. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A method for reading out a sensor cell, comprising the steps of:
-
(a) asserting a sensor current, indicative of a sensed value, from the sensor cell to an input node of a readout circuit; and (b) operating the readout circuit in response to the sensor current to generate an output voltage indicative of the sensed value while clamping the input node at a potential that is at least substantially fixed. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15)
-
Specification