Conductive path compensation for matching output driver impedance

摘要

A method for matching output impedance of a driver to a load impedance. In representative embodiments an external impedance is attached between an external contact and a first source potential, wherein the load impedance includes the external impedance plus impedance of interconnections between an output terminal of the driver and the external impedance. An adjustable impedance, which can be field effect transistors which can be turned on separately and in combination to change the value of the adjustable impedance and which can be located on an integrated circuit, are connected between a second source potential and the output terminal of the driver. A reference potential, wherein the reference potential has a value half-way between the first source potential and the second source potential is obtained. And a load matching impedance is obtained by changing the adjustable impedance until the absolute value of the difference between the voltage of the output terminal of the driver and the reference potential is less than a preselected value.