Design And Implementation Of The Test System Of LED Driver Chip With Bist On ATE

With the advantages of energy-saving,environmental protection,safety,reliability,long operating life,small size and higher than 50-200lm/w light efficiency,the LED lighting has lower power comsumption than the previous general lighting in the same lighting effects.It does not contain toxic mercury like fluorescent lamps or ultraviolet radiation.Accordingly,LED lighting research has been an inevitable trend.Its driver is one aspect of LED light source which is different from other light sources,thus the research of driving technology becomes the key point of LED lighting development.In the wake of the increasing scale of IC design,the testability design method of combinational circuits as difficult as SOC becomes more and more important.As the testability technology generally is embeded the test generation and the logic of response analysis into the circuit,the die is more controllable and observability,which creates that the fault coverage of chip test is broadened and the test time is significantly shortened,futher more,the development cycle of chips is cut down.This thesis designs and develops a test scheme of a LED constant current driver with built-in Self Test.The whole test scheme is divided into two parts according to the type of the test platform: one is based on STS8200 ATE is used for the evaluation of project design,and mainly used for internal validation test and failure analysis.And another is based on ETS88 that brings about the design requirements of testability module for product testing,which covers the introduction of test project development process and the test debugging in engineering phase.Firstly,the test scheme based on the STS8200 platform mainly verifies the correctness of the design of the circuit,provides test data for the designers’ development analysis during early research,the evaluation reversion,and the laboratory reliability test verification,etc.This thesis introduces the characteristics of the STS8200 platform system,as well as the design scheme of the hardware circuit and software program based on the platform.The thesis evidently analyses the result of this platform’ scheme and illustration.Secondly,the test scheme based on ETS88 platform has the advantages of platform stability,feasibility of module testing,testing efficiency and strong readability of writing interface.In this thesis,the hardware index of ETS88 and the software structure of test system are available.According to the design scheme,the flow chart of the whole program,the project test plan,the design test circuit board and the flow of the test program function on the platform are used.During the engineering stage,it excludes the special factor and abnormity through debugging optimization,which ensures that the test parameters are accurate and stable in the production process.Finally,in the chapter of the data analysis section,on account of the testing system analysis in the important content of Six Sigma management,various control charts are generated through MINITAB 16 to evaluate and monitor the various stages of the process.It effectively assures that project development meets the specified requirements,reach the accuracy of the test,and remain at an acceptable and stable level for a long time.This thesis is about the research of a circuit within the chip’s testability,and it contains hardware design and software development of testability circuit combining both analog and digital driver board,which is based on the existing ATE test platform hardware indicators and software structure.It also achieves the intended purpose of chip design.What’s more,it creates a lot of valuable practical cases and practical experience for the sake of the following more complex built-in test design chip test scheme.