高精度晶体振荡器芯片设计研究
发布时间：2018-11-03 12:39
【摘要】：晶体振荡器作为现代电子系统和电子设备的频率源,广泛应用于通信、导航、雷达、车载电子以及精密时频计量仪器等领域。温度频率稳定度是晶体振荡器的重要性能指标之一,普通的晶体振荡器因为石英晶体的谐振频率随温度发生偏移,导致其温度频率稳定度不高,无法满足高端产品对频率稳定度的严苛要求。目前有热敏电阻补偿技术、模拟温度补偿技术、数字温度补偿技术和微处理器温度补偿技术改善晶体振荡器的温度频率特性。本论文设计了一款高精度晶体振荡器芯片,产生10M、40M和50M三个频点的弦波信号。首先采用Colpitz结构设计了振荡电路,对振荡电路的起振、线性小信号模型和相位噪声进行了理论分析,并基于理论分析优化了相位噪声性能;随后基于AT切晶体设计了一种结构新颖的模拟温度补偿电路产生对温度呈三次方的补偿电压改善晶体振荡器的频率温度稳定度,该电路包括可调的PTAT电流源、可调的CTAT电流源、可调的非线性电流源、电流求和模块以及可调的电流-电压转换器。通过改变可调电阻的值和译码器的控制字分别实现低温段零温系数点和高温段零温系数点可调;最后提出了采用人工神经网络对晶体振荡器的温度频率特性进行校正的方案,构建了基于人工神经网络的温度补偿晶体振荡器系统,由包括人工神经网络的温度补偿电压产生模块、时序控制模块和振荡模块组成,并阐述了该系统的三个工作过程:训练数据采集、神经网络训练和工作阶段。本设计晶体振荡电路和模拟温度补偿电路分别在TSMC25um BCD工艺和GSMC13um RF工艺下流片,版图面积分别为1130×700um2和120×180um2。晶体振荡器测试结果如下:外形尺寸1.2 mm×1 mm×0.8 mm,能够工作在3.3V和5V电源电压下,工作温度范围-40?C~+85?C,10M、40M和50M三个频点的功耗分别是8mA、9mA和11mA,输出幅度分别是5.6dBm、5.1dBm和5.1dBm,二次谐波抑制分别是-37dBm、-36dBm和-36d Bm,相位噪声性能是:10M:≤-124dBc/Hz@100Hz;≤-150dBc/Hz@1kHz;≤-158dBc/Hz@10kHz.40M:≤-111dBc/Hz@100Hz;≤-139dBc/Hz@1kHz;≤-149dBc/Hz@10kHz.50M:≤-102dBc/Hz@100Hz;≤-137dBc/Hz@1kHz;≤-150dBc/Hz@10kHz-40?C~+100?C的温度范围内,温度频率稳定度的仿真结果是±5ppm。
[Abstract]:Crystal oscillator, as the frequency source of modern electronic system and electronic equipment, is widely used in the fields of communication, navigation, radar, onboard electronics and precision time-frequency measurement instruments. The temperature frequency stability is one of the important performance indexes of crystal oscillator. Because the resonance frequency of quartz crystal deviates with temperature, the temperature frequency stability is not high. Unable to meet the stringent requirements of high-end products for frequency stability. At present, there are thermistor compensation technology, analog temperature compensation technology, digital temperature compensation technology and microprocessor temperature compensation technology to improve the temperature and frequency characteristics of crystal oscillator. In this paper, a high precision crystal oscillator chip is designed to generate three frequency chord wave signals of 10 MN 40 M and 50 M. Firstly, the oscillation circuit is designed with Colpitz structure. The oscillation circuit, linear small signal model and phase noise are analyzed theoretically, and the phase noise performance is optimized based on the theoretical analysis. Then a novel analog temperature compensation circuit based on AT crystal is designed to improve the frequency and temperature stability of the crystal oscillator. The circuit includes adjustable PTAT current source and adjustable CTAT current source. Adjustable nonlinear current source, current summation module and adjustable current-voltage converter. By changing the value of the resistor and the control word of the decoder, the zero temperature coefficient point of the low temperature section and the zero temperature coefficient point of the high temperature section can be adjusted respectively. Finally, an artificial neural network is proposed to correct the temperature and frequency characteristics of the crystal oscillator, and a temperature compensated crystal oscillator system based on the artificial neural network is constructed. It is composed of temperature compensation voltage generation module, timing control module and oscillation module including artificial neural network. The three working processes of the system are described: training data collection, neural network training and working stage. The crystal oscillation circuit and the analog temperature compensation circuit are designed in TSMC25um BCD process and GSMC13um RF process respectively. The layout area is 1130 脳 700um2 and 120 脳 180 um2, respectively. The test results of the crystal oscillator are as follows: the shape size of 1.2 mm 脳 1 mm 脳 0.8 mm, can work at 3.3V and 5V power supply voltages, and the power consumption at the operating temperature range of -40C ~ 85C _ (10) M ~ (10) M ~ (40) M and 50 M is 8 Ma ~ (9) Ma and 11 Ma, respectively. The output amplitudes are 5.1dBm and 5.1dBm, and the second harmonic suppression is -37dBmg-36dBm and -36d Bm, phase noise respectively: 10m: 鈮，
本文编号：2307816
[Abstract]:Crystal oscillator, as the frequency source of modern electronic system and electronic equipment, is widely used in the fields of communication, navigation, radar, onboard electronics and precision time-frequency measurement instruments. The temperature frequency stability is one of the important performance indexes of crystal oscillator. Because the resonance frequency of quartz crystal deviates with temperature, the temperature frequency stability is not high. Unable to meet the stringent requirements of high-end products for frequency stability. At present, there are thermistor compensation technology, analog temperature compensation technology, digital temperature compensation technology and microprocessor temperature compensation technology to improve the temperature and frequency characteristics of crystal oscillator. In this paper, a high precision crystal oscillator chip is designed to generate three frequency chord wave signals of 10 MN 40 M and 50 M. Firstly, the oscillation circuit is designed with Colpitz structure. The oscillation circuit, linear small signal model and phase noise are analyzed theoretically, and the phase noise performance is optimized based on the theoretical analysis. Then a novel analog temperature compensation circuit based on AT crystal is designed to improve the frequency and temperature stability of the crystal oscillator. The circuit includes adjustable PTAT current source and adjustable CTAT current source. Adjustable nonlinear current source, current summation module and adjustable current-voltage converter. By changing the value of the resistor and the control word of the decoder, the zero temperature coefficient point of the low temperature section and the zero temperature coefficient point of the high temperature section can be adjusted respectively. Finally, an artificial neural network is proposed to correct the temperature and frequency characteristics of the crystal oscillator, and a temperature compensated crystal oscillator system based on the artificial neural network is constructed. It is composed of temperature compensation voltage generation module, timing control module and oscillation module including artificial neural network. The three working processes of the system are described: training data collection, neural network training and working stage. The crystal oscillation circuit and the analog temperature compensation circuit are designed in TSMC25um BCD process and GSMC13um RF process respectively. The layout area is 1130 脳 700um2 and 120 脳 180 um2, respectively. The test results of the crystal oscillator are as follows: the shape size of 1.2 mm 脳 1 mm 脳 0.8 mm, can work at 3.3V and 5V power supply voltages, and the power consumption at the operating temperature range of -40C ~ 85C _ (10) M ~ (10) M ~ (40) M and 50 M is 8 Ma ~ (9) Ma and 11 Ma, respectively. The output amplitudes are 5.1dBm and 5.1dBm, and the second harmonic suppression is -37dBmg-36dBm and -36d Bm, phase noise respectively: 10m: 鈮，
本文编号：2307816
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