Research And Design Of New Type Of Pseudo-random Photoelectric Encoder Chip

Photoelectric encoder,also known as photoelectric angular displacement encoder,is a modern digital angle measuring device with high precision and small size.Therefore,it is widely used in modern industry,national defense and other fields,is one of the most widely used sensors.With the higher requirement for photoelectric encoder,it is of great scientific and practical significance to develop a new type of photoelectric encoder with higher integration and higher precision.Because of the real-time output characteristics,absolute photoelectric encoder is becoming an important direction in the research of photoelectric encoder.To solve the problem of large volume and low precision for traditional absolute encoder,an absolute encoder chip based on the M-code pseudo-random code was designed.Finally,the encoder chip is implemented and tested with the test system.The theoretical basis of the new pseudo-random encoder chip is Moore fringe theory and pseudo-random coding theory,which is different from the traditional design using a single coding method.This design combine pseudo-random coding theory and Moore fringe coding theory with the help of the internal ADC.The resolution of the photoelectric encoder improves greatly without increasing the size of the chip.In chip design,the chip architecture is introduced first,and referring to the characteristics of incremental and absolute signal links,the internal circuit design of the chip is introduced.The chip tapes out after the completion of the layout and verification work.At the end of the paper,the chip testing work is introduced to show that the resolution of the chip is 19 bit,the electrical response frequency is greater than 200 k Hz,and the current consumption is less than 100 m A.Which means that the chip meets all the design requirements.The original work of this article includes: proposing a new type of absolute photoelectric encoder theory,elaborating its theoretical basis and system design.Designing a new encoder chip architecture,planning the layout accordingly and completing the chip design.The chip is fabricated in 0.35 ?m CMOS process,the size is 5×3mm2,the resolution of this photoelectric encoder is 19 bit.,which can meet the requirement of practical application.