Testing is an essential step in the production of electronic devices. In the manufacture of integrated circuits plays an important functional testing, ie, verification of compliance device parameters expected parameters. Static and dynamic characteristics determine the performance of operational amplifiers and testing for these parameters is one of the necessary stages of the production of these products.
The problem or task
The task was to develop a system that performs testing of operational amplifiers. It is necessary to check such parameters as: signal gain, dynamic characteristics, amplitude-frequency characteristic.
To solve the problem, an experimental system was created that automatically tests operational amplifiers. After starting the program, the following characteristics of the operational amplifier are sequentially tested: gain, signal rise time, signal rise rate, signal fall time, signal decay rate, a graph of the amplitude-frequency characteristic is plotted. The operator has the opportunity to observe the progress of testing. At the end of testing, a report is displayed on the screen. The report includes test results, service information (date, number of tests, their execution time), frequency response graph. The testing technique consisted in feeding test pulses of a rectangular and sinusoidal form to the input of the operational amplifier circuit and then collecting and processing signals from its output. The software was written in the NI TestStand environment using API functions developed in the NI LabVIEW programming environment that execute individual tests. In the process of creating API functions, NI SCOPE device drivers were used for working with digitizers and NI FGEN for working with signal generators. The system is built on the PXI platform with the NI PXI-8108 embedded controller. It also includes an NI PXI-5422 Arbitrary Waveform Generator and an NI PXI-5122 Digitizer. Thus, in a short time and with a limited budget, an experimental system was created that allows solving the problem of testing operational amplifiers.