Linearizing circuits for a semiconductor pressure transducer

Claim 1

A linearizing circuit apparatus for a differential transducer of the type employing a conventional Wheatstone bridge array having first and second input terminals for applying a source of biasing potential therebetween and first and second output terminals for obtaining a transducer output voltage therebetween, with said transducer undesirably providing a non-linear output voltage for both a positive and a negative voltage difference between said output terminals, said linearizing circuit apparatus operative to linearize said output voltage for both said positive and negative voltage differences comprising: (a) first and second amplifiers each having a non-inverting and an inverting input terminal and an output terminal, with the non-inverting input terminal of said first amplifier coupled to said first output terminal of said bridge, and the non-inverting input terminal of said second amplifier coupled to said second output terminal of said bridge; (b) input means coupling said inverting input terminals of said first and second amplifiers together; (c) first threshold means coupled between the output terminal and the inverting input terminal of said first amplifier and second threshold means coupled between the output terminal and the inverting input terminal of said second amplifier; (d) feedback means coupling said output terminals to said input means, to cause said first amplifier to operate when said voltage at said first bridge output terminal exceeds the voltage at said second bridge output terminal with said second threshold means operative to bypass said second amplifier, and to cause said second amplifier to operate when said voltage at said second bridge output terminal exceeds the voltage at said first bridge output terminal with said first threshold means operative to bypass said first amplifier and means for coupling the output terminals of said first and second amplifiers to one of said input terminals of said bridge array.