复旦大学：《集成电路工程》教学资源（硕士士学位论文）差分结构数字控制晶体振荡器设计

学校代码：10246 学号：11210720101 復大孥 硕士学位论文 差分结构数字控制晶体振荡器设计 院 系： 信息科学与工程学院 专 业： 集成电路工程 姓 名： 褚博 指导教师： 唐长文副教授 完成日期： 2013年4月25日

学校代码：10246 学 号：11210720101 硕 士 学 位 论 文 差分结构数字控制晶体振荡器设计 院 系： 信息科学与工程学院 专 业： 集成电路工程 姓 名： 褚 博 指 导 教 师： 唐长文 副教授 完 成 日 期： 2013 年 4 月 25 日

目录 图目录… …川 表目录… …V 摘要… VI Abstract.......................... …X 第一章概述…。 …1 1.1研究背景… …1 1.2论文研究的内容和贡献… …2 1.3论文组织结构… 3 第二章晶体振荡器概述… S 2.1晶体振荡器的分类… 5 2.2晶体谐振特性… 5 2.2.1晶体的压电特性… …6 2.2.2晶体的电学等效模型及品质因子…6 2.3振荡器的分析方法…9 2.3.1反馈系统分析… 9 2.3.2阻抗分离法…… 10 2.4常见晶体振荡器的结构 11 2.4.1单端晶体振荡器… 11 2.4.2差分晶体振荡器 14 第三章可变电容特性分析… …17 3.1可变电容的分类… …17 3.2可变电容特性分析 19 第四章相位噪声分析… …25 4.1相位噪声基本概念… 25 4.1.1振荡器中的相位噪声. 25 4.1.2相位噪声的影响… 27 4.2相位噪声的脉冲敏感函数分析法 28 4.2.1线性时不变分析…28 4.2.2线性相位时变分析…30 4.3相位噪声的矢量分析法…36 4.3.1振荡器的电流通路…36

I 目录 图目录 ··························································································· III 表目录 ··························································································· V 摘要 ···························································································· VII Abstract ······················································································· IX 第一章 概述 ···················································································· 1 1.1 研究背景············································································· 1 1.2 论文研究的内容和贡献 ··························································· 2 1.3 论文组织结构 ······································································· 3 第二章 晶体振荡器概述 ····································································· 5 2.1 晶体振荡器的分类 ································································· 5 2.2 晶体谐振特性 ······································································· 5 2.2.1 晶体的压电特性 ··························································· 6 2.2.2 晶体的电学等效模型及品质因子 ······································ 6 2.3 振荡器的分析方法 ································································· 9 2.3.1 反馈系统分析 ······························································ 9 2.3.2 阻抗分离法 ································································ 10 2.4 常见晶体振荡器的结构 ·························································· 11 2.4.1 单端晶体振荡器 ·························································· 11 2.4.2 差分晶体振荡器 ·························································· 14 第三章 可变电容特性分析 ································································· 17 3.1 可变电容的分类 ··································································· 17 3.2 可变电容特性分析 ································································ 19 第四章 相位噪声分析 ······································································· 25 4.1 相位噪声基本概念 ································································ 25 4.1.1 振荡器中的相位噪声 ···················································· 25 4.1.2 相位噪声的影响 ·························································· 27 4.2 相位噪声的脉冲敏感函数分析法 ·············································· 28 4.2.1 线性时不变分析 ·························································· 28 4.2.2 线性相位时变分析 ······················································· 30 4.3 相位噪声的矢量分析法 ·························································· 36 4.3.1 振荡器的电流通路 ······················································· 36

4.3.2噪声电流源到输出电压的传输函数…38 4.3.3非线性电路对幅度调制和相位调制的响应…39 4.3.4谐振电路对噪声电流源的响应…42 4.3.5白噪声源的分解… 45 4.3.6矢量分析法在振荡器中的应用 47 第五章差分晶体振荡器电路设计… 49 5.1设计指标分析… 49 5.2振荡器核心电路… 51 5.2.1核心电路结构 51 5.2.2大信号分析 55 5.2.3电流源偏置电路… 58 5.2.4数控开关电容阵列… 59 5.2.5输出级设计… 59 5.3版图及仿真结果 60 第六章总结与展望… 65 6.1总结… …65 6.2展望… 65 参考文献… …67 致谢… …71

II 4.3.2 噪声电流源到输出电压的传输函数 ·································· 38 4.3.3 非线性电路对幅度调制和相位调制的响应 ························· 39 4.3.4 谐振电路对噪声电流源的响应 ········································ 42 4.3.5 白噪声源的分解 ·························································· 45 4.3.6 矢量分析法在振荡器中的应用 ········································ 47 第五章 差分晶体振荡器电路设计 ························································ 49 5.1 设计指标分析 ······································································ 49 5.2 振荡器核心电路 ··································································· 51 5.2.1 核心电路结构 ····························································· 51 5.2.2 大信号分析 ································································ 55 5.2.3 电流源偏置电路 ·························································· 58 5.2.4 数控开关电容阵列 ······················································· 59 5.2.5 输出级设计 ································································ 59 5.3 版图及仿真结果 ··································································· 60 第六章 总结与展望 ·········································································· 65 6.1 总结·················································································· 65 6.2 展望·················································································· 65 参考文献 ······················································································· 67 致谢 ····························································································· 71

图目录 图1-1晶体振荡器类型及结构...… .2 图2-1晶体的电学等效模型 6 图2-2串联谐振、并联谐振阻抗的频率响应曲线7 图23谐振处的晶体阻抗的频率响应曲线 图2-4振荡器的正反馈模型 9 图2-5RLC并联电路的脉冲响应..... .10 图2-6振荡器的负阻模型。 11 图2-7(a)Pierce振荡器(b)Colpitts振荡器(c)Santos振荡器......12 图2-8(a)Santos振荡器电路(b)小信号等效模型.…。 .12 图2-9有源电路阻抗 13 图2-10阻抗Zc的极坐标表示.... .13 图2-11交叉耦合差分对管 .15 图2-12差分晶体振荡器 .15 ....… 图3-1(a)PN结电容结构(b)电容-电压特性 .17 图3-2PMOS电容及电容-电压特性 .18 图3-3反型MOS管电容及其电容-电压特性 19 图3-4累积型MOS管可变电容及其电容-电压特性 .19 图35不同偏置电压下的电容一电压特性曲线 20 图3-6振荡器的电路通路。 20 图3-7电容的符号函数形式 21 图3-8电容的电流-电压曲线 22 图4-1振荡器噪声时域、频域表示 25 图4-2振荡器的输出频谱.… 26 图4-3振荡器相位噪声的典型曲线。 27 图4-4接收机前端及信号下变频过程 28 图4-5电感电容振荡器线性等效模型 28 图4-6振荡器相位噪声示意图... 29 图4-7被电流脉冲激励的LC振荡器. 31 图4-8LC振荡器对冲击激励的相应 .32 图4-9SF等效系统 .33 公

III 图目录 图 1-1 晶体振荡器类型及结构 ......................................................................... 2 图 2-1 晶体的电学等效模型 ............................................................................ 6 图 2-2 串联谐振、并联谐振阻抗的频率响应曲线 ............................................. 7 图 2-3 谐振处的晶体阻抗的频率响应曲线 ........................................................ 8 图 2-4 振荡器的正反馈模型 ............................................................................ 9 图 2-5 RLC 并联电路的脉冲响应 ................................................................... 10 图 2-6 振荡器的负阻模型 .............................................................................. 11 图 2-7 (a) Pierce 振荡器 (b)Colpitts 振荡器 (c)Santos 振荡器 ...................... 12 图 2-8 (a)Santos 振荡器电路 (b)小信号等效模型 .......................................... 12 图 2-9 有源电路阻抗 ..................................................................................... 13 图 2-10 阻抗 Zc 的极坐标表示 ....................................................................... 13 图 2-11 交叉耦合差分对管 ............................................................................ 15 图 2-12 差分晶体振荡器 ................................................................................ 15 图 3-1 (a)PN 结电容结构 (b)电容-电压特性 .................................................. 17 图 3-2 PMOS 电容及电容-电压特性 .............................................................. 18 图 3-3 反型 MOS 管电容及其电容-电压特性 ................................................. 19 图 3-4 累积型 MOS 管可变电容及其电容-电压特性 ...................................... 19 图 3-5 不同偏置电压下的电容—电压特性曲线 .............................................. 20 图 3-6 振荡器的电路通路 .............................................................................. 20 图 3-7 电容的符号函数形式 .......................................................................... 21 图 3-8 电容的电流-电压曲线 ......................................................................... 22 图 4-1 振荡器噪声时域、频域表示 ................................................................ 25 图 4-2 振荡器的输出频谱 .............................................................................. 26 图 4-3 振荡器相位噪声的典型曲线................................................................ 27 图 4-4 接收机前端及信号下变频过程 ............................................................. 28 图 4-5 电感电容振荡器线性等效模型 ............................................................ 28 图 4-6 振荡器相位噪声示意图 ....................................................................... 29 图 4-7 被电流脉冲激励的 LC 振荡器 .............................................................. 31 图 4-8 LC 振荡器对冲击激励的相应 .............................................................. 32 图 4-9 ISF 等效系统 ...................................................................................... 33

图4-10器件噪声到相位噪声的转变 .35 图4-11振荡器的电流通路...… 37 图4-12噪声的旋转矢量表示 39 图4-13非线性电路模型.. 39 图4-14相位调制量的混频过程 40 图4-15非线性电路对噪声的调制.... .42 图4-16对振荡器施加外部电流激励..... 42 图4-17相位调制与幅度调制..… 44 图4-18幅度调制电流和相位调制电流对应的阻抗 45 图4-19周期性准稳态噪声.. .45 图4-20ω(0的傅里叶展开.... 46 图4-21矢量分解. .46 图5-1晶体的阻抗响应曲线.. 50 图5-2差分晶体振荡器核心电路 51 图5-3等效小信号电路图. 52 图5-4电路的环路增益和相位.. 53 图5-5核心电路的电源抑制比...… 54 图5-6振荡电压与沟道电流关系 55 图5-7(a)A类振荡器(b)C类振荡器。 56 图5-8NMOS管导通角与栅极直流电压偏置关系 57 图5-9电流源偏置电路 58 图5-10电源抑制仿真结果...… 58 图5-11(a)电容阵列(b)单位电容结构 59 图5-12电路输出级设计 60 图5-13电路整体版图.… 60 图5-14相位噪声仿真结果 61 图5-15频率调谐曲线 61 图5-16经过缓冲级后的瞬态波形 62 图5-17电源抑制比 62 图5-18频率牵引. 63 N

IV 图 4-10 器件噪声到相位噪声的转变.............................................................. 35 图 4-11 振荡器的电流通路 ............................................................................ 37 图 4-12 噪声的旋转矢量表示 ........................................................................ 39 图 4-13 非线性电路模型 ............................................................................... 39 图 4-14 相位调制量的混频过程 ..................................................................... 40 图 4-15 非线性电路对噪声的调制 ................................................................. 42 图 4-16 对振荡器施加外部电流激励.............................................................. 42 图 4-17 相位调制与幅度调制 ........................................................................ 44 图 4-18 幅度调制电流和相位调制电流对应的阻抗 ........................................ 45 图 4-19 周期性准稳态噪声 ............................................................................ 45 图 4-20 ω(t)的傅里叶展开 .............................................................................. 46 图 4-21 矢量分解 .......................................................................................... 46 图 5-1 晶体的阻抗响应曲线 .......................................................................... 50 图 5-2 差分晶体振荡器核心电路 ................................................................... 51 图 5-3 等效小信号电路图 .............................................................................. 52 图 5-4 电路的环路增益和相位 ....................................................................... 53 图 5-5 核心电路的电源抑制比 ....................................................................... 54 图 5-6 振荡电压与沟道电流关系 ................................................................... 55 图 5-7 (a) A 类振荡器 (b) C 类振荡器............................................................ 56 图 5-8 NMOS 管导通角与栅极直流电压偏置关系 .......................................... 57 图 5-9 电流源偏置电路 ................................................................................. 58 图 5-10 电源抑制仿真结果 ............................................................................ 58 图 5-11 (a)电容阵列 (b)单位电容结构 ........................................................... 59 图 5-12 电路输出级设计 ............................................................................... 60 图 5-13 电路整体版图 ................................................................................... 60 图 5-14 相位噪声仿真结果 ............................................................................ 61 图 5-15 频率调谐曲线 ................................................................................... 61 图 5-16 经过缓冲级后的瞬态波形 ................................................................. 62 图 5-17 电源抑制比....................................................................................... 62 图 5-18 频率牵引 .......................................................................................... 63