Patent ID: 8618866
Filing Date: 2013-12-31
Classification: G09G,G11C

Abstract:
1. A voltage matching circuit for matching voltages in first and second circuits comprising: a comparator circuit having a first input coupled to a first supply voltage point of the first circuit and a second input coupled to a second supply voltage point of the second circuit, the comparator circuit configured to output a variable error voltage that is varied based on a comparison of voltages input to the first and second inputs and is related to the difference in voltage between the first and second supply voltage points, wherein the first and second supply voltage points are operative to receive first and second supply voltages, respectively; at least one variable current control circuit operatively coupled to at least one of the first and second supply voltage points, and responsive to the variable error voltage to vary a current between one of the first and second supply voltage points and a common potential point in order to match the first and second supply voltages; and a transistor coupled between one of the first and second supply voltage points and the common potential point and having an input to receive the voltage error signal and responsive to the voltage error signal to vary current passing through the transistor based on the values of the voltage error signal.