Research On The Key Technologies Of Digital Oscilloscope Verification Standard

Digital oscilloscope is one of the most important instruments for failure analysis or routine inspection of the electronic equipment,therefore ensuring the traceability of its magnitude is particularly significant.During the calibration cycle,periodic checking of digital oscilloscope,which is commonly used in the laboratory,could test its usage state and whether the value of its measurement is accurate.The verification standard is a standard instrument for periodic checking.Firstly,this paper reviews the present research and the research meaning of digital oscilloscope's periodic checking.After that,it establishes system technical item and makes a overall design plan according to the design method of instrument system.Finally,it discusses the key point of the periodic checking standard technology to achieve the designning of the circuit.The verification standard is designed to generate standard sinusoidal signal,standard DC voltage signal and standard fast rising signal,to check the Oscilloscope's main parameters like bandwidth and so on.The generation of sinusoidal signal is based on direct digital frequency synthesis technology.The frequency of sinusoidal signal can achieve 300 MHz and the accuracy rating is less than 0.025%.Based on pipeline technology,we use two 12 bit DAC to generate DC voltage signal,so that the resolution can achieve 6?V and the accuracy rating is much less than 0.025%.The employment of Schottky diode current characteristics and nonlinear transmission line structure generates the fast rising edge signal,which has a rising edge of 110 ps.Finally this paper tests the reliability and stability of the verification standard through the uncertainty calculation,which can prove the reliability and stability meet the standards.