Method and device for analog-digital conversion, comprises a comparator delivering a pair of control signals to an increment-decrement block for computing new digital value

摘要

The device (20), that is an analog-digital converter, computes a sequence of output digital values (S14) representative of an input analog signal (S10), and comprises a comparator (22) for comparing the input analog signal with a comparison analog signal (S11) and for delivering a pair of control signals (S12, S13) when the absolute value for the difference between the two signals is greater than a threshold value, an increment-decrement block (24) for computing a new output digital value on receiving the control signal, and a converter (26) for obtaining the comparison analog signal on the basis of the last computed output digital value. The device also comprises a time counter (28) delivering a digital value (S15) corresponding to the time lapsed since the reception of the preceding control signal. The increment-decrement block (24) comprises a memory element wherein the value of the control signal is stored, and a computing unit for evaluating the new output digital value. The new value of the control signal is written in the memory element when the comparator (22) sends a write request. The converter (26) comprises a memory element wherein the output digital value is stored, and a digital-analog converter. The new digital value is written in the memory element when a write request is received from the increment-decrement block (24). The method for analog-digital conversion is claimed and includes the steps for determining the comparison analog signal, comparing the input analog signal to the comparison analog signal, and computing a new digital value when the absolute value of the difference between the two signals is greater than a threshold value. When the input analog signal is greater than the comparison analog signal with determined threshold, the new output digital value is computed by increasing the last output digital value by a determined increment, and when the comparison analog signal is greater than the input analog signal with determined threshold, the new output digital value is computed by decreasing the last output digital value by a determined decrement.