DC/DC PMBus Compliance Tester
Examensarbete för masterexamen
Digital power management involves the ability to manage and configure a DC/DC converter with commands through a communication system. The Power Management Bus (PMBus) is an open standard protocol that can be implemented in a power management system for controlling the power converters on a printed circuit board. The advantage of this standard is that the system designer can easily transmit commands to any PMBus device without having to consider which device is used. Another advantage is that power converters can be replaced by other converters as long as they are compliant with the PMBus standard. Also, an previously used PMBus implementation can be reused and another PMBus device can be substituted as long as the standard is followed. It is therefore important that the chosen PMBus device is compliant with the standard and will behave as commanded. A PMBus device should be tested early in a product design phase for PMBus compliancy otherwise problems may be introduced late in the design phase and that can be costly. Therefore, a PMbus compliance tester would be beneficial. However, such test system does not exist today. This report presents a PMBus compliancy tester, i.e. an automated test system that checks and verifies if a PMBus device is compliant with the standard. The system is modifiable and tests are modified by the use of script files. For this purpose an new script language has been defined, offering the test engineer the possibility to adjust each script file independently. The script file defines the commands and the parameters to be tested. When the script file is executed by the test system a log file with all the desired test results is produced. This flexibility makes the test system developed in this project superior to any existing automated test system. The tester is implemented as a LabView program featuring a graphical user interface. Verification measurements are performed via a GPIB interface that controls an oscilloscope, a power supply and an electronic load. Each script command is implemented as a separate sub-program and a main program calls the sub-program when the corresponding script command is identified by a parser. This approach makes it possible to substitute an instrument without having to redo more than one sub-program. Therefore the modularity of this tester is believed to be an benefit in a laboratory environment where instruments are frequently replaced and occupied.
Elektroteknik och elektronik , Informations- och kommunikationsteknik , Electrical Engineering, Electronic Engineering, Information Engineering , Information & Communication Technology