Patent ID: 6369732
Filing Date: 2002-04-09
Classification: H03M

Abstract:
A low voltage fully differential analog-to-digital converter including an input stage provided with a plurality of differential input cells for producing pre-amplified signals, a successive processing unit for receiving said pre-amplified signals from said input stage, and a decoding output stage for receiving signals from said successive processing stage, wherein each said differential input cell comprising:a first differential amplifier having two transistors, the sources of said transistors connected together and connected with a low supplied voltage through a current source, the drains of said two transistors connected to a first output terminal and a second output terminal, respectively, and the gates of said resistors connected to a first input terminal and a reference voltage branch, respectively; a second differential amplifier having two transistors, the sources of said transistors connected together and connected with a low supplied voltage through a current source, the drains of said two transistors connected to said first output terminal and said second output terminal, respectively, and the gates of said resistors connected to a second input terminal and said reference voltage branch, respectively; a bias impedance having a first terminal and a second terminal, said first terminal connected to a high supplied voltage and said second terminal connected to said first and said second output terminals of said differential input cell through respective pieces of load bearing impedance to adjust output voltages of said first and second output terminals; and an impedance branch having a first impedance connecting said second output terminal of said differential input cell and a first output terminal of an adjacent differential input cell, and having a second impedance connecting said second terminal of said bias impedance of said differential input cell and a second terminal of a bias impedance of said adjacent differential input cell.