Analog-to-digital converter with a decision circuit and an optimized decision threshold

Abstract

The device includes a decision circuit () for providing, by comparing the amplitude of a received modulated signal (Sr) to a decision threshold (Vth, Th), a binary signal (Sb) with two states respectively representing first and second binary values that respectively correspond to low and high values of the received signal. A counting module () activated during successive time periods calculates a differential numerical value (DN, SDN) representing the algebraic difference between the two numbers of bits of the binary signal that respectively have the second binary value and the first binary value. At the end of each time period, an adjustment module () increases or decreases the threshold value (Vth, Th) by an increment (Dth) according to whether the sign (SDN) of the difference is respectively positive or negative. Application in particular to systems for transmitting digital data at high bit rates over optical connections.