Patent ID: 6756858
Filing Date: 2004-06-29
Classification: H03H

Abstract:
A method for matching output impedance of a driver to a load impedance, comprising:attaching an external impedance between an external contact and a first source potential, wherein the load impedance comprises the external impedance plus impedance of interconnections between an output terminal of the driver and the external impedance; attaching an adjustable impedance between a second source potential and the output terminal of the driver; obtaining a reference potential, wherein the reference potential has a value half-way between the first source potential and the second source potential; obtaining a load matching impedance by changing the adjustable impedance until the absolute value of the difference between voltage of the output terminal of the driver and the reference potential is less than a preselected value; repeating the method obtaining the load matching impedance for a preselected number of conducting traces, wherein the conducting traces have different length to width ratios; based on the conducting trace length to width ratio of an additional driver, selecting the load matching impedance which provides the closest match of the output impedance to the load impedance for the additional driver; and transferring an instruction to the additional driver to set the load matching impedance of the additional driver to the result of the method step of selecting the load matching impedance.