Device for reducing the range of the resistance values of individual transmission paths of a cross fitting - circuit to a minimum and a method for minimizing the range of the resistance values of the individual transmission paths

摘要

A crossoint switching circuit in which the transmission paths through the circuit are compensated such that the resistance from any input to any output is equal to the resistance from any other input to any other output. This is accomplished by varying the resistance of the metallization in the circuit according to a prescribed method. The varying of the metallization resistance is accomplished by varying the width and length of metallization from the output or input package pins to the circuit. This width variation either adds or reduces resistance to the particular switching path indicated by the prescribed method. The prescribed method entails ascertaining that set of transmission paths having a maximum of resistance between inputs and outputs, and thereafter systemmatically adding resistance to other transmission paths to bring their resistances up to this maximum without adding to the maximum already established. This is accomplished by first compensating those circuit paths having resistances next highest to the ascertained maximum. Thereafter all transmission paths are compensated in descending order. If there is no possibility of raising the resistance of a particular transmission path to the ascertained maximum without raising another transmission path resistance past the ascertained maximum, then the resistance of this particular transmission path is raised to the ascertained maximum which raises certain other transmission paths past the ascertained maximum by a certain amount. This certain amount if then added to all paths not affected by the above addition, such that a minimum resistance spread is achieved between the possible paths in the switching circuit network.