Patent ID: 7049993
Filing Date: 2006-05-23
Classification: H03M

Abstract:
1. An analog-to-digital converter comprising: analog input terminals to which analog input signals are supplied; an input terminal selection circuit to select one of said analog input terminals; preset registers provided for said analog input terminals; preset data registers to store preset data; a preset data selection circuit to select and provide one of said preset data to said preset registers; a preset register selection circuit to select one of said preset registers which corresponds to the one of said analog input terminals selected by said input terminal selection circuit; a digital-to-analog conversion circuit to convert an output of said preset data registers into an analog voltage; a sampling capacitor; and an analog-to-digital conversion circuit which provides said sampling capacitor with an output of said digital-to-analog conversion circuit for a pre-charge duration of a sampling period and the input voltage at the one of said analog input terminals selected by said input terminal selection circuit for a sampling duration of said sampling period and which compares a voltage of said sampling capacitor with a predetermined reference voltage to convert the input voltage into digital data for a conversion duration, wherein said analog-to-digital converter selects said preset data in response to kinds of the input voltages applied for said input terminals.