Patent ID: 6731231
Filing Date: 2004-05-04
Classification: H03M

Abstract:
A circuit for analogue to digital conversion comprising:a sample and hold circuit (1) connected to a coarse analogue to digital converter (2) which is connected to a digital to analogue converter (3) which is connected to combining logic circuitry and; a fine analogue to digital converter (6); wherein the circuit is characterised by a voltage to current converter (7; R1) connected to the output of the sample and hold circuit (1); and to means for subtracting in the current domain having its inputs connected to theâ€”current converter and to the digital to analogue converter; means for summing at a virtual earth node (9); and means for converting the output current of the substracting means to a current to voltage (10; R2) at the input to the fine analogue to digital converter (6).