Input offset voltage is one of the most critical parameters of operational amplifier circuits.With the devel-opment of integrated circuits,high-precision operational amplifiers have become a trend,and input offset voltage is decreasing.In most cases,laser trimming is employed during wafer testing to meet usage requirements,posing higher demands on chip testing.The typical method for testing operational amplifier input offset voltage involves a"Device under Test(DUT)-Auxiliary Op-Amp"test setup,where the necessary condition is that the positive and negative input terminals as well as the output terminal of the DUT are connected to the auxiliary loop for testing.However,with the advancement of integrated circuits,circuits such as current amplification circuits have internal amplifier stages without external pins,rendering the typical"DUT-Auxiliary Op-Amp"test method inadequate.This paper proposes a signal amplification loop scheme and designs a testing system based on the T861 ATE to address the testing of offset voltage for operational amplifiers with only input terminals accessible.The proposed system achieves a testing accura-cy of up to 0.5uV.
维普
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