I/F Conversion Circuit Nonlinear Compensation And The Study Of The Digital I/F Converter

The main objective is to improve the output frequency linearity of a class ofcurrent-frequency converter. This paper is in-depth analysis of the current frequencyconverter works, and the characteristics of the output and input signal. And thenselect the ADI’s ADuC847chip as the main chip, and the way of the compensationof the output error to improve the linearity of the converter. Throughout the designprocess, this article is to be considered from two aspects of the hardware andsoftware, and strive to improve the practicality of the design system.Firstly, this apaper is in-depth analysis of the operating principle of the type ofcurrent frequency converter, and on this basis, to design a signal conditioning circuitand the current compensation circuit. In the design of the compensation algorithm,to make the compensation algorithm have a true reflection of the system error,we analysis a large number of experimental samples data, and ultimately get thecharacteristic curve of the output frequency error of the current-frequency converterchips, and design the appropriate compensation algorithm on the basis. In thecompensationexperiment we use the compensation algorithm and a compensationcircuit to have got better compensation. However, due to the serious drift of theconverter itself, causing the compensate drop in long work, this paper try to explorethe use of digital synthesis methods to design the current-frequency converter, inorder to get better current frequency converter.In order to improve the ease of debugging monitoring system, this paper designa simple, convenient test system based on VC++to test system peripheral circuit module and the output signal.The test system are proven to meet the requirements ofsystem debugging.Finally taking into account the electromagnetic interference of the systemand the complexity of work site, this paper, from the two aspects of the hardwareand software, design a set of protective measures, thus ensuring the system reliableand stable under a variety of harsh electromagnetic environment.