ATE Test And Simulation Research Of Buck DC/DC Switching Power Supply Chip

The switching power management chip can be divided into two types:AC/DC and DC/DC.The DC/DC converter technology and process are mature and standardized both at home and abroad.With the continuous improvement of integration,the probability of failures introduced in the manufacturing process of DC/DC switching power supply chips is getting higher and higher,and the test problems are becoming more and more complicated.Introducing the test of the DC/DC switching power supply chip to the ATE（Automatic Test Equipment,automatic test equipment）test platform can achieve rapid and effective detection of defects in the chip while reducing test costs.This article mainly introduces the ATE test development process of a synchronous rectified BUCK PWM switching power supply SM54310 chip on the TR6850 mixed signal test system.Analyze and solve the problems found in actual production testing to achieve optimized test plan design.At the same time,through the TINA-TI software to build a circuit to simulate the chip function parameters,the chip ATE test results were verified.The main content of this article includes the following aspects:1.Based on the switching power supply test theory and TR6850 mixed signal test system,the thesis designs and builds an ATE test platform for the synchronous rectifier BUCK type DC/DC switching power supply SM54310 chip.In the design and construction of the hardware test environment,the thesis developed test fixtures and selected the TR6850mixed-signal test machine based on chip test requirements and functional parameter characteristics.Designed the test schematic diagram in Cadence software and completed the PCB design of the test board.Based on the C++language,the thesis wrote an ATE test program,including the testing of electrical parameters such as operating voltage range,quiescent current,oscillator frequency,and on-resistance.There are 145 test items at room temperature,low temperature,and high temperature.In the study of designing ATE test procedures,the thesis adopted more mature test methods in engineering（such as direct measurement method,scanning test method,etc.）.At the same time,the paper also uses the indirect test method of on-resistance and the card boundary value test method of slow start time,etc.,which can significantly optimize the test time and improve the test stability.The test results show that the test result of static working current（fs=350k Hz）is16m A～20m A,the test result of voltage adjustment rate is about 0.007%/V,the test result of load adjustment rate is about 0.07%/A,and the test result of reference voltage is 0.876V～0.894V,the test result of on-resistance is 60mΩ～100mΩ.The thesis also conducted a failure analysis of the failures that occurred during the production automation test phase,and optimized the design from three aspects of hardware design,test procedures,and test stability and efficiency.The pass rate of the test items of the parameters specified in the final chip manual reached 100%,the yield after three-temperature batch screening exceeded 91%,and the test time was around 9s.The pass rate of the test items of the parameters specified in the final chip manual reached 100%,the yield after the three-temperature batch screening was increased to 91%,and the test time was reduced to about 9s,which realized the stable and efficient automated testing of the SM54310switching power supply chip.2.Using TINA-TI software,the SM54310 switching power supply chip was simulated.According to the actual application environment of the chip and the test schematic diagram,the paper establishes the simulation circuit model of the SM54310 switching power supply chip.Based on the simulation circuit model,using TINA-TI software,the thesis carried out DC analysis and transient simulation analysis on the output voltage ripple,oscillator frequency,external slow start time and working efficiency parameters.The simulation results show that the output voltage ripple simulation result is 27.5m V when the output current is 3A.The internal setting frequency simulation results are 353.4k Hz and 552.7k Hz respectively,and the external setting frequency simulation results are in the range of280k Hz to 700k Hz.When the ground-to-ground capacitance C_SSis 47n F,the slow start simulation time is 5.84ms.The maximum operating efficiency of the chip in the output current range of 0～3A has reached 93%.In the light load range,the operating efficiency can also reach more than 80%.The effectiveness of the above method and platform is verified through testing and simulation,which provides a reference for the ATE test and development of DC/DC switching power supply chips.