Patent ID: 7030801
Filing Date: 2006-04-18
Classification: H03M

Abstract:
1. An apparatus for converting an analog signal to a digital signal, the apparatus comprising: a plurality of capacitors including at least a first capacitor, a second capacitor and a third capacitor, a first capacitor associated with a first capacitance, a second capacitor associated with a second capacitance, a third capacitor associated with a third capacitance, the first capacitance being substantially equal to the second capacitance, the second capacitance being substantially equal to the third capacitance; a plurality of resistors including at least a first resistor and a second resistor, the first resistor associated with a first resistance, a second resistor associated with a second resistance, the first resistance being substantially equal to the second resistance; an operational amplifier including at least a first input terminal, a second input terminal and an output terminal; wherein the first capacitor includes a first capacitor terminal and a second capacitor terminal, the second capacitor includes a third capacitor terminal and a fourth capacitor terminal, the third capacitor includes a fifth capacitor terminal and a sixth capacitor terminal, and the first capacitor terminal, the third capacitor terminal, and the fifth capacitor terminal are coupled to the first input terminal; wherein the second input terminal is coupled to a first voltage; wherein each of the second capacitor terminal, the fourth capacitor terminal, and the sixth capacitor terminal is capable of being coupled to anyone of the first voltage, an analog voltage, a second voltage, and a third voltage, the analog voltage associated with the analog signal; wherein the first resistor includes a first resistor terminal and a second resistor terminal, the second resistor includes a third resistor terminal and a fourth resistor terminal, the first resistor terminal is coupled to the second voltage, the fourth resistor terminal is coupled to the first voltage, the first resistor and the second resistor being in series; wherein the plurality of resistors corresponds to a plurality of resistor terminals, each of the plurality of resistors including two of the plurality of resistor terminals; wherein the third voltage is provided by opening or closing a plurality of switches, each of the plurality of switches directly coupled to one of the plurality of resistor terminals; wherein the apparatus is configured to convert the analog signal to the digital signal and is associated with a process related to a successive approximation register; wherein the process includes processing information associated with the analog voltage and a fourth voltage; adjusting the fourth voltage in response to information associated with the analog voltage and the fourth voltage, and determining the digital signal based on at least information associated with the fourth voltage; wherein the fourth voltage is associated with at least a first voltage level of the second capacitor terminal, a second voltage level of the fourth capacitor terminal and a third voltage level of the sixth capacitor terminal, the first voltage level, the second voltage level and the third voltage level each being selected from a group consisting of the first voltage, the second voltage and the third voltage.