Patent ID: 6977606
Filing Date: 2005-12-20
Classification: H03M

Abstract:
1. An analog-to-digital converter of a pipeline type for converting an analog signal to a digital signal, comprising: a plurality of arithmetic circuits arranged in accordance with a bit length of said digital signal, and connected in series; and an output circuit providing said digital signal based on bit data provided from each of said plurality of arithmetic circuits, wherein each of said plurality of arithmetic circuits includes: an analog-to-digital sub-converter converting an input voltage received in a sample mode to said bit data, and providing said bit data, a digital-to-analog sub-converter converting said bit data to an analog voltage, sample hold portion sampling first and second input voltages received in first and second operation modes in said sample mode, respectively, and holding the sampled first and second input voltages in first and second voltage holding portions, respectively, adding portion adding the voltages held in said sample hold portion, and subtracting portion subtracting the analog voltage of said bit data from a voltage produced by the addition by said adding portion, and providing a voltage produced by the subtraction to the arithmetic circuit in the next stage, and said subtracting portion operates, in a third operation mode, to subtract said analog voltage from said voltage produced by the addition, and to output a voltage produced by the subtraction as said first input voltage for the next stage, and operates, in a fourth operation mode, to subtract said analog voltage from said voltage produced by the addition, with said first and second voltage holding portions interchanged with each other, and to output a voltage produced by the subtraction as said second input voltage for the next stage.