US 2018/0005684 A1 · Reading Circuit with a Shifting Stage and Corresponding Reading Method

Abstract

A reading circuit for a charge-retention circuit stage is provided with a storage capacitor coupled between a first biasing terminal and a floating node, and a discharge element coupled between the floating node and a reference terminal. The reading circuit further has an operational amplifier having a first input terminal that is coupled to the floating node and receives a reading voltage, a second input terminal receives a reference voltage, and an output terminal on which it supplies an output voltage, the value of which is a function of the comparison between the reading voltage and the reference voltage and indicative of a residual charge in the storage capacitor. A shifting stage shifts the value of the reading voltage of the floating node, before the comparison is made between the reading voltage and the reference voltage for supplying the output voltage.

Claims22

Dependent claims

A circuit, comprising:

a charge-retention circuit stage for measurement of a time interval, the charge-retention circuit stage having a storage capacitor coupled between a first biasing terminal and a floating node, and also having a discharge element coupled between the floating node and a reference terminal, the discharge element designed to implement discharge of a charge stored in the storage capacitor by leakage through a corresponding dielectric,
an operational amplifier having a first input terminal coupled to the floating node and designed to receive a reading voltage, a second input terminal designed to receive a reference voltage, and an output terminal configured to supply an output voltage that has a value that is a function of a comparison between the reading voltage and the reference voltage and is indicative of a residual charge in the storage capacitor during its discharge;
and
a shifting stage, configured to carry out a shift of the value of the reading voltage of the floating node, before performing the comparison between the reading voltage and the reference voltage to supply the output voltage indicative of the residual charge in the storage capacitor during its discharge.

1 more element

A circuit, comprising:

a capacitive charge storage element having a first electrode coupled to a floating node and a second electrode coupled to a first voltage node;
a charge flow circuit coupled to the floating node, the charge flow circuit comprising a plurality of elementary discharge elements coupled in series between the floating node and a second voltage node, wherein the capacitive charge storage element has a larger charge retention capacitance than the charge flow circuit;
and
a switching circuit with an output coupled to the first voltage node and selectively coupled to the second voltage node, the switching circuit having a first input coupled to a ground reference terminal and a second input coupled to a shift voltage terminal.

1 more element

Dependencies are inferred from the claim text.

Reading Circuit with a Shifting Stage and Corresponding Reading Method

Life of this patent

Reading Circuit with a Shifting Stage and Corresponding Reading Method

Life of this patent

Abstract

Claims22