A precision trim technique for monolithic analog circuits

A technique for permanent adjustment of precision analog circuits at wafer test by selective shorting of Zener diodes is presented. Analytical details of the trimming procedure and a physical description of diode short-circuiting are given. The method is applied to a precision operational amplifier with input offset voltage reduced to 10 /spl mu/V. The necessity of optimizing other related parameters is demonstrated. Practical considerations limiting wafer test accuracy are discussed. Circuit performance is summarized.