Patent ID: 6583744
Filing Date: 2003-06-24
Classification: H03M

Abstract:
A current correction circuit comprising:a first current generating circuit operational to produce a first replica current equal to a most significant bit (MSB) unit cascode device base current associated with a MSB segment of a digital-to-analog converter (DAC); a second current generating circuit operational to produce a second replica current equal to a total device base current of an R-2R ladder circuit portion of a least significant bit (LSB) segment of a DAC; a third current generating circuit operational to produce a third replica current equal to a total device base current of an output switch portion of the LSB segment of a DAC; a first high impedance summing circuit operational to sum the second and third replica currents and generate a negative current equal to a total combined device base current associated with the LSB segment of the DAC; and a second high impedance summing circuit operational to sum the first replica current with the negative current to generate a correction current therefrom such that the correction current is equal to a current difference between an MSB unit and the LSB segment.