数字陀螺中电流舵DAC的设计
发布时间：2018-07-18 12:21
【摘要】：随着微机械惯性系统广泛的被用于军事产品和民用产品中,对微机械陀螺性能的要求越来越高。由于数字陀螺具有高速的算法处理能力以及较好的稳定性,它已经成为陀螺的主要发展方向之一,具有十分光明的前景。而DAC是连接数字与模拟电路之间的桥梁,是数字陀螺接口电路的重要组成部分,其精度和速度直接影响了数字陀螺的性能。因此,对于数模转换器的研究具有重要研究价值及实用意义。本文主要内容是设计一种16位的电流舵DAC。经过对电流舵DAC结构分析,采用了6+6+4分段式结构,这种分段形式能够有效地减少芯片面积、提高线性度。在电路设计中,为了降低电路非线性和不匹配等非理想因素的影响,加入了数据加权(DWA)算法来减小电流舵结构中的电流源失配问题。在时序上,通过同步锁存器,使开关控制信号同步。并且通过降低时钟控制信号的交叉点,减小了电流源互补开关同时打开产生的毛刺。除此之外,为了给电流源偏置电路提供稳定的参考电流源,设计了具有较低温度系数的自启动带隙基准电路,其基准电压温度系数为15.47ppm/oC。在电流舵DAC的采样频率为500KHz下,六个单独的电流源模块能够实现稳定电流输出,输出电流分别为30n A、60n A、120n A、240n A、480n A、30.72u A。在数字陀螺有效输入信号频率为4KHz下,整体DAC电路的微分非线性(DNL)和积分非线性(INL)分别为0.41LSB和0.75LSB,建立时间为0.4112us,电路输出电压区间为0V-4.5V,无杂散动态范围(SFDR)为62.5d B.符合设计要求。
[Abstract]:With the wide application of micro-mechanical inertial system in military and civil products, the performance of micro-mechanical gyroscope is becoming more and more important. Digital gyroscope has become one of the main developing directions of gyroscope because of its high speed algorithm processing ability and good stability. It has a bright future. DAC is a bridge between digital and analog circuits and an important part of digital gyro interface circuit. Its precision and speed directly affect the performance of digital gyroscope. Therefore, the study of D-A converter has important research value and practical significance. The main content of this paper is to design a 16-bit current rudder DAC. By analyzing the structure of the current steering DAC, a 664 segmented structure is adopted, which can effectively reduce the chip area and improve the linearity. In order to reduce the influence of non-ideal factors such as nonlinearity and mismatch in circuit design data weighted (DWA) algorithm is added to reduce the current source mismatch in the current rudder structure. In timing, the switch control signal is synchronized by synchronous latch. By lowering the cross point of clock control signal, the burr produced by the current source complementary switch is reduced simultaneously. In addition, in order to provide a stable reference current source for the current source bias circuit, a self-starting band-gap reference circuit with low temperature coefficient is designed, with a reference voltage temperature coefficient of 15.47 ppm / oc. At the sampling frequency of 500kHz, the six single current source modules can realize stable current output with the output current of 30nAnA60n AH120n Aton 240n Aton 480nAm 30.72u A. The differential nonlinearity (DNL) and integral nonlinearity (INL) of the whole DAC circuit are 0.41LSB and 0.75LSBrespectively under the effective input signal frequency of the digital gyroscope is 4kHz, the setting time is 0.4112us, the output voltage range is 0V-4.5V, and the SFDR is 62.5dB. Meet the design requirements.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN792
本文编号：2131888
[Abstract]:With the wide application of micro-mechanical inertial system in military and civil products, the performance of micro-mechanical gyroscope is becoming more and more important. Digital gyroscope has become one of the main developing directions of gyroscope because of its high speed algorithm processing ability and good stability. It has a bright future. DAC is a bridge between digital and analog circuits and an important part of digital gyro interface circuit. Its precision and speed directly affect the performance of digital gyroscope. Therefore, the study of D-A converter has important research value and practical significance. The main content of this paper is to design a 16-bit current rudder DAC. By analyzing the structure of the current steering DAC, a 664 segmented structure is adopted, which can effectively reduce the chip area and improve the linearity. In order to reduce the influence of non-ideal factors such as nonlinearity and mismatch in circuit design data weighted (DWA) algorithm is added to reduce the current source mismatch in the current rudder structure. In timing, the switch control signal is synchronized by synchronous latch. By lowering the cross point of clock control signal, the burr produced by the current source complementary switch is reduced simultaneously. In addition, in order to provide a stable reference current source for the current source bias circuit, a self-starting band-gap reference circuit with low temperature coefficient is designed, with a reference voltage temperature coefficient of 15.47 ppm / oc. At the sampling frequency of 500kHz, the six single current source modules can realize stable current output with the output current of 30nAnA60n AH120n Aton 240n Aton 480nAm 30.72u A. The differential nonlinearity (DNL) and integral nonlinearity (INL) of the whole DAC circuit are 0.41LSB and 0.75LSBrespectively under the effective input signal frequency of the digital gyroscope is 4kHz, the setting time is 0.4112us, the output voltage range is 0V-4.5V, and the SFDR is 62.5dB. Meet the design requirements.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN792
【参考文献】
相关期刊论文 前2条
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