Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
221 words
A successive-approximation analog-to-digital converter comprising: comparator means for producing an output in response to an input thereto exceeding a predetermined threshold voltage; a plurality of binary weighted capacitors, including first and second one-half unit capacitors comprising a unit capacitance, each of the capacitors having a first terminal coupled in common to the input of the comparator means, and a second terminal; voltage reference means for producing at least first and second predetermined reference voltages, and an offset voltage having a predetermined value between the first and second reference voltages; sample means, operative during a sample phase, for storing a sample of an unknown analog input voltage on the largest of the capacitors while shorting the comparator means, and for simultaneously coupling the second terminals of each of the other capacitors except the first one-half unit capacitor to the first reference voltage while coupling the second terminal of the first one-half unit capacitor to the offset voltage; and successive-approximation means, operative during a conversion phase following said sample phase, for converting said sample to a binary representation thereof by successively coupling the second terminals of the capacitors, from the largest to the smallest, to the second reference voltage, and, in response to each such coupling which produces the output from the comparator means, recoupling such second terminal to the first reference voltage.
Claim 2
Dependent Claim
221 words
A successive-approximation analog-to-digital converter comprising: comparator means for producing an output in response to an input thereto exceeding a predetermined threshold voltage; a plurality of binary weighted capacitors, including first and second one-half unit capacitors comprising a unit capacitance, each of the capacitors having a first terminal coupled in common to the input of the comparator means, and a second terminal; voltage reference means for producing at least first and second predetermined reference voltages, and an offset voltage having a predetermined value between the first and second reference voltages; sample means, operative during a sample phase, for storing a sample of an unknown analog input voltage on the largest of the capacitors while shorting the comparator means, and for simultaneously coupling the second terminals of each of the other capacitors except the first one-half unit capacitor to the first reference voltage while coupling the second terminal of the first one-half unit capacitor to the offset voltage; and successive-approximation means, operative during a conversion phase following said sample phase, for converting said sample to a binary representation thereof by successively coupling the second terminals of the capacitors, from the largest to the smallest, to the second reference voltage, and, in response to each such coupling which produces the output from the comparator means, recoupling such second terminal to the first reference voltage.
Claim 3
Dependent Claim
66 words
An analog-to-digital converter according to claim 1 wherein the successive-approximation means are further characterized as successively coupling the second terminals of each of the capacitors except the second one-half unit capacitor, from the largest to the smallest, to the second reference voltage, and, in response to each such coupling which produces the output from the comparator means, recoupling such second terminal to the first reference voltage.