| The "Sensing City" era is approaching.Hall sensor technology is applied in the traditional industry,like National defense technology,transportation and industrial automation.Besides,Hall sensor technology is occupied the remarkable share of the emerging application field in the recent years,such as in the modern measurement,automotive industry,and consumer electronics.All of above developments undoubtedly enhance the innovation and progress of Hall sensor technology.As a result,in response to the demand for Hall sensors in emerging application fields with high integration,high accuracy and digitization,this dissertation will design and implement a digital programmable linear Hall sensor with integrated EEPROM unit.Main points are following: 1.This article designed an EEPROM unit and a matched programming function which are suit for Hall sensors.Based on the storage requirements of the Hall sensor system,this unit total storage capacity set at 192 bits,which is divided into 8 pages with 24 bits data capacity per page.Users can program the chip by the VCC and VOUT pins,saving the needed digital codes into the EEPROM unit.Different from other programs,users can adjust the digital codes of the voltage reference,current reference,clock frequency,sensitivity,and quiescent output voltage.The integration of EEPROM unit cater to the high integration development and improves the Hall sensors’ performance in different application scenarios and conditions.2.According to the research of offset voltage cancellation technology,using the Quad Hall Elements Rotating current technology combined with Chopper Stabilization Technology to eliminate offset voltage.During the process,the Common center symmetrically arranged offset voltage of the Quad Hall Elements can be partially offset.After modulating and demodulating the circuit,magnetic field signal DC output,but the offset voltage is separated from the magnetic field signal in the frequency domain and remains at high frequency.Another filtering the high frequency offset voltage by a low-pass filter,output the accurate DC magnetic field signal.Using this technology could significantly decrease the offset voltage,at the same time reduces the effect of mechanical stress on the Hall sensor and achieves higher sensing accuracy.3.Due to the research of the sensor system architecture.This dissertation designs a system architecture associated with programming functions and an analog signal path in which digital signals participate in the regulation are designed.The digital circuit selects the required data from the EEPROM unit,which is grounded on the application environment’s requirements,generates calibration values that adjusts the analog signal path to realize the adjustment of the Hall sensors’ sensitivity and quiescent output voltage according to the linear interpolation temperature compensation algorithm.This architecture describes the sensors’ stable sensitivity and quiescent output voltage over the entire temperature range,improves the chip’s adaptability and expands the application fields of Hall sensors.4.The key circuit module of Hall sensor is designed in this article and verified by simulation.The whole design not only includes the module in the analog signal path,but also the bandgap reference module,clock generation module,high voltage generation module,EEPROM unit and quiescent output voltage reference module.Among the formula derivation and simulation verification,the functions and performance of each module are normal among,and the indicators fit in the expected design goals.According to an overseas 0.18μm BCD process,and using EDA tools like Schematic Edit and Specture on the Cadence platform,this dissertation makes the circuit design and simulation verification.Moreover,the final three steps are designing the layout,taping out the IC and completing the test of samples.At last,the test data and consequence indicate the functions of the programmable Hall sensor are standard and the parameters meet the expected design demands. |
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