Microminiature integrated circuit impedance device including weighted

Abstract

A microminiature terminal-adjustable integrated circuit impedance device comprising a substrate, a plurality of impedance elements formed on the substrate with each impedance element having an impedance, a first input terminal, an output terminal, a plurality of electrically permanently alterable contactless switching elements formed on the substrate, each of the switching elements being associated with one of the plurality of impedance elements and having initially a first switching state and being permanently alterable by application of electrical energy to an opposite switching state, an interconnecting means interconnecting the impedance elements and the switching elements in a first circuit configuration between the first input terminal and the output terminal such that the impedance between the first input terminal and the output terminal is of a first value, and a plurality of adjustment terminals each being connected to a different one of the plurality of switching elements for facilitating the application of electrical energy thereto to cause such switching elements to change to the opposite switching state, whereby the application of electrical energy to selected ones of the adjustment terminals causes a second circuit configuration having a preselected second value to be formed between the first input terminal and the output terminal. Each electrically permanently alterable contactless switching element is comprised of fusible conductive links or shortable diodes, singly or in combination. In the preferred embodiment the device comprises resistive elements fabricated with state-of-the-art thin film or monolithic integrated circuit technology and serves as a variable resistor or as a variable voltage divider performing the function of a fixable contactless trimming potentiometer.