Patent ID: 8036020

Claim:
A circuit for reading from an electronic charge retention element for a time measurement, of the type comprising at least one capacitive element with a dielectric exhibiting a leakage and a transistor with an isolated control terminal for reading residual charges, comprising: first and second parallel branches between two power supply terminals, each branch comprising at least one transistor of a first type and at least one transistor of a second type, a first transistor of the second type of the first branch being the transistor with the isolated terminal and configured to read the charge retention element, and a first transistor of the second type of the second branch receiving, on its control terminal, a stepped signal, wherein the respective drains of the transistors of the first type are connected to the respective inputs of a comparator having its output providing an indication of the residual voltage level in the charge retention element, and wherein each branch comprises a second transistor of the second type having its control terminals connected at the output of an amplifier of application of a reference voltage, said voltage being also applied on a conduction terminal of the transistor with the isolated terminal.