High-speed High-precision Adc Testing Techniques

With today's electronic information technology developing rapidly, ADCs, as digital and analog interface circuit, are also getting continuous development towards the direction of high-speed high-precision. This trend is accompanied with the growing demands for its testing methods and means. As a result of its high-speed high-precision's characteristics, in the actual application, the factors such as driving,clock,grounding,bypass and power will lead to a more serious lowering of the performance parameters than to the common ADCs, thereby making its evaluation become more difficult. Simultaneously because the overseas developed countries have been keeping to China implementing high-speed high-precision ADC restrictions on the export licence system (for ADCs of eight bits, speed limited to less than 500 MHz; for 10 bits ones, speed less than 200 MHz; and more bits, more strictly will be the speed limited), so it is quite difficult to access the advanced ADC test technology. Therefore, the effective research and exploration of high-precision high-speed ADC testing technology is of great practical significance.By selecting the high-speed high-precision ADC sampling - TI company's 10 Bit, 40Msps pipeline ADC ADS822, referring to foreign ADC evaluation board design experience, making a careful study of the matching relationship between different parts, A variety of components required for the evaluation board were selected and the purchased with evaluation board schematics mapped out at the same time. After a detailed discussion of the various issues which should be considered in high-speed PCB design, and through the use of the appropriate place and route, the layout diagram of ADS822 evaluation board was drawn and the prototype board was fabricated with all component welded on it later. Finally based on the designed ADS822 evaluation board and the existing laboratory equipment, a ADC test platform was built to evaluation chip performance. Then by developing the test plan, the chip test has been carried on. By above, thus a effective way for high-precision high-speed ADC testing technology has been explored and studied.Main content and results include the following four aspects. 1. A detailed description about the ADC's basic performance parameters and the main testing methods was given respectively, including the typical static and dynamic parameters, accompanied with the corresponding density histogram testing method and the fast Fourier transform test method.2. The basic circuit composition module of an ADC Evaluation Board was identified. The mutual match relations for each main module like driving circuit, the clock circuit with ADC under test was analyzed, then according to that, primary components and devices were selected with ADS822 evaluation board schematic diagram being drawn using Protell99se.3. After taking fully into account signal integrity (SI), power integrity (PI) and the integrity of the electromagnetic (EMI) requirements, a detailed research was carried on the place and route of ADC evaluation board. Then based on that, a four-storey ADS822 Evaluation Board was designed,fabricated and welded.4. The basic composition module of an ADC evaluation system was identified with respective performance indicators being shown. An ADC test system has been built using the existing laboratory test installation.The evaluation results show that the idea through the design and construction of ADC evaluation board and test system for high-speed high-precision ADC test is entirely feasible.