Digital-Compatible Testing Scheme for Operational Amplifier
This paper presents a digital-compatible testing scheme for operational amplifier (op amp). In the proposed scheme, the op amp device under test (DUT) is configured to a unity-gain buffer which is responded to a testing pulse, could be realized by a ring oscillator circuit. The output of the configured unity-gain buffer is digitized by simple digital counter and then the digitized counting number is compared to a predetermined critical value to evaluate the op amp DUT. The digitized counting number is sensitive to the specification of op amp DUT and easily to be observed in the digital domain. The testing parameters of testing setup of stimulus, testing result, testing accuracy, and testing time are also investigated to detail the proposed scheme. Digital compatibility and simplicity are main advantages of the proposed testing scheme. In addition, no complicated analog comparator and reference voltages are required. Behavioral and circuit level simulations are performed to show the effectiveness of the proposed scheme.
testing scheme operational amplifier (op amp) device under test (dut) unity-gain buffer digital compatible