device for converting an analog, balanced signal (v? 71i? 71n? 71 +, v? 71i? 71n? 71) to a digital signal by laddningsomfordelning in a number of capacitive element

摘要

PCT No. PCT/SE87/00110 Sec. 371 Date Dec. 2, 1987 Sec. 102(e) Date Dec. 2, 1987 PCT Filed Mar. 5, 1987 PCT Pub. No. WO87/06078 PCT Pub. Date Oct. 8, 1987.An apparatus for converting an analog, balanced signal (VIN+, VIN-) to a digital signal by charge redistribution in a plurality of capacitors (1-5, 1'-5'). These are grouped in two sets and at least during an approximating phase can be selectively connected to two different reference voltages (VR, earth) with the aid of switches (6-10, 6'-10'). The sets of capacitors are each arranged to act on the potential at their respective points (13,13') during an approximating phase and a comparator (15) is adapted for comparing the potentials at these points. The switches are controlled by a means (18) for sampling and approximating logic which generates digital control words in response to the comparison result, of the comparator.