Patent ID: 6934669

Claim:
A method for measuring cross-coupling capacitance, comprising: providing at least first and second wires; charging the first wire to a predetermined voltage; performing a first measurement associated with a capacitance of the first wire; charging the second wire to the predetermined voltage; recharging the first wire to the predetermined voltage; performing a second measurement associated with a capacitance of the first wire; and calculating a difference between the first and second measurements to determine the cross-coupling capacitance between the first and second wires; coupling a first transistor between a supply voltage and a common node, coupling a second transistor in series with the first transistor between the common node and ground, wherein the first wire is coupled to the common node; applying a first periodic signal to a gate of the first transistor and a second periodic signal to a gate of the second transistor, to periodically charge and discharge the first wire; and further including: a) grounding the second wire for a first period of time; b) during the first period of time, applying the first periodic signal to the gate of the first transistor and the second periodic signal to the gate of the second transistor to charge and discharge the first wire, wherein the first and second transistors are not activated simultaneously; c) repeatedly performing the first measurement during the first period of time and averaging a result of the first measurement; d) wherein the charging of the second wire occurs for a second period of time; e) during the second period of time, applying the first periodic signal to the gate of the first transistor and the second periodic signal to the gate of the second transistor to charge and discharge the first wire, wherein the first and second transistors are not activated simultaneously; f) repeatedly performing the second measurement during the second period of time and averaging a result of the second measurement; and g) wherein calculating the difference between the first and second measurements includes taking the difference between the averaged results of the first and second measurements.