Patent ID: 7626529

Claim:
A method for digitizing an analog quantity (V E ) produced by a detector of electromagnetic radiation, in particular infrared radiation, said detector comprising a matrix of juxtaposed elementary sensors, whose interactions with said radiation generate said analog quantity (V E ), the method comprising the steps consisting, for each line or for each column of said matrix: in carrying out a first integration phase of said analog quantity over a first time interval using an integrator stage; in ordering the interruption of said first integration phase via a comparator stage whereof one input is connected to the output of said integrator stage and the other input to a reference circuit delivering a reference value (V ref ); in converting the analog quantity thereby integrated (V S ) to a first numerical value (B) via a binary counter and a memory element connected to the output of said comparator stage; in storing said first numerical value (B) in the form of a first binary number representing the most significant bits; wherein said method further comprises the steps consisting, for each line or for each column of said matrix: in converting said first numerical value (B) thereby obtained to an analog signal (V DAC ) similar to the analog quantity to be digitized (V E ) via an analog-to-digital converter; in subtracting said analog signal (V DAC ) from said analog quantity to be digitized (V E ); in amplifying the signal (V E −V DAC ) resulting from said subtraction with a gain representing said first numerical value (B); in carrying out a second integration phase using said integrator stage, in order to produce a second numerical value (M) proportional to the analog signal thereby amplified 2 B ·(V E −V DAC ) and forming a second binary number representing the least significant bits; in adding said first (B) and second (M) numerical values in order to form a number (N) representative of said analog quantity to be integrated (V E ).