赛普拉斯CapSense入门手册

【实例截图】

【核心代码】

目录
CapSense®入门.......................................................................................................................................................................1
目录 ........................................................................................................................................................................................3
1. 简介 .................................................................................................................................................................................7
1.1 如何使用本指南 .....................................................................................................................................................7
1.2 赛普拉斯的 CapSense 文档系统............................................................................................................................7
1.3 赛普拉斯 CapSense 产品.......................................................................................................................................9
1.3.1 赛普拉斯 CapSense 的优点 ......................................................................................................................9
1.4 文档规范..............................................................................................................................................................10
2. CapSense 技术.............................................................................................................................................................11
2.1 电容式感应方法 ...................................................................................................................................................11
2.1.1 自电容.....................................................................................................................................................11
2.1.2 互电容.....................................................................................................................................................12
2.2 自电容等效模型 ...................................................................................................................................................12
2.3 CapSense 感应技术.............................................................................................................................................13
2.3.1 感应方法 .................................................................................................................................................13
2.3.2 电容转换 .................................................................................................................................................13
2.3.3 含 Sigma Delta 调制器的 CapSense（CSD） ........................................................................................13
2.3.4 含 Sigma Delta 调制器的增强型 CapSense（CSDPLUS） ....................................................................14
2.3.5 CapSense 逐次逼近电磁兼容（CSA_EMC）.........................................................................................15
2.3.6 SmartSense_EMCplus（SmartSense 电磁兼容于 CY8C20XX7/S 系列）..............................................16
2.4 CapSense 调试....................................................................................................................................................17
2.4.1 定义 ........................................................................................................................................................17
2.4.2 信噪比（SNR）......................................................................................................................................17
2.4.3 SNR 的测量 ............................................................................................................................................18
2.4.4 SmartSense 自适应调节 .........................................................................................................................19
2.4.5 SmartSense_EMC（SmartSense 电磁兼容）........................................................................................20
2.5 传感器类型...........................................................................................................................................................20
2.5.1 按键（零维传感器） ...............................................................................................................................21
2.5.2 滑条（一维传感器） ...............................................................................................................................22
2.5.3 触摸屏和触控板（两维传感器）..............................................................................................................23
2.5.4 接近感应传感器（三维传感器）..............................................................................................................23
目录
CapSense®入门 文档编号：001-91943 版本*A 4
2.6 传感器结构...........................................................................................................................................................24
2.6.1 铜线耦合电场（PCB）............................................................................................................................24
2.6.2 通过弹簧/垫圈/泡沫耦合电场...................................................................................................................25
2.6.3 通过电子印墨耦合电场............................................................................................................................25
2.6.4 通过玻璃上的 ITO 薄膜耦合电场.............................................................................................................25
2.7 用户界面反馈.......................................................................................................................................................26
2.7.1 视觉反馈 .................................................................................................................................................26
2.7.2 触觉反馈 .................................................................................................................................................30
2.7.3 听觉反馈 .................................................................................................................................................31
2.8 防水功能..............................................................................................................................................................33
2.8.1 水滴和水流对 CapSense 产生的影响......................................................................................................34
2.8.2 驱动屏蔽信号和屏蔽电极 ........................................................................................................................35
2.8.3 保护传感器..............................................................................................................................................36
2.8.4 水属性对防水功能的影响 ........................................................................................................................37
2.9 CapSense 系统概述.............................................................................................................................................38
2.9.1 硬件组件 .................................................................................................................................................38
2.9.2 固件组件 .................................................................................................................................................38
3. 设计的注意事项 .............................................................................................................................................................40
3.1 覆盖层选择...........................................................................................................................................................40
3.1.1 覆盖层材料..............................................................................................................................................40
3.1.2 覆盖层厚度..............................................................................................................................................41
3.1.3 覆盖层粘合剂..........................................................................................................................................41
3.2 ESD 保护.............................................................................................................................................................42
3.2.1 防止 ESD 放电 ........................................................................................................................................42
3.2.2 重定向.....................................................................................................................................................43
3.2.3 钳制 ........................................................................................................................................................43
3.3 电磁兼容性（EMC）注意事项 .............................................................................................................................44
3.3.1 辐射干扰及辐射.......................................................................................................................................44
3.3.2 抗传导干扰和辐射...................................................................................................................................53
3.4 软件滤波..............................................................................................................................................................53
3.4.1 均值滤波器..............................................................................................................................................54
3.4.2 IIR 滤波器 ...............................................................................................................................................55
3.4.3 中值滤波器..............................................................................................................................................57
3.4.4 抖动滤波器..............................................................................................................................................58
3.4.5 基于事件的滤波器...................................................................................................................................60
3.4.6 基于规则的滤波器...................................................................................................................................60
3.5 功耗 .....................................................................................................................................................................60
3.5.1 有效电流和睡眠电流 ...............................................................................................................................60
3.5.2 平均电流 .................................................................................................................................................61
3.5.3 响应时间与功耗.
目录
CapSense®入门 文档编号：001-91943 版本*A 5
3.6.3 接近感应传感器设计 ...............................................................................................................................65
3.6.4 影响接近感应距离的因素 ........................................................................................................................66
3.7 引脚分配..............................................................................................................................................................71
3.8 PCB 布局指南......................................................................................................................................................73
3.8.1 寄生电容 CP ............................................................................................................................................73
3.8.2 电路板的各个层.......................................................................................................................................73
3.8.3 板厚 ........................................................................................................................................................74
3.8.4 按键设计 .................................................................................................................................................74
3.8.5 滑条设计 .................................................................................................................................................75
3.8.6 传感器和器件放置...................................................................................................................................81
3.8.7 走线长度和宽度.......................................................................................................................................82
3.8.8 走线路由 .................................................................................................................................................82
3.8.9 串扰解决方案..........................................................................................................................................83
3.8.10 过孔 ........................................................................................................................................................84
3.8.11 接地层.....................................................................................................................................................84
3.8.12 电源的布局建议.......................................................................................................................................85
3.8.13 屏蔽电极和保护传感器............................................................................................................................87
3.8.14 使用单层 PCB 进行设计 CapSense 系统 ................................................................................................90
4. CapSense 产品系列......................................................................................................................................................91
4.1 赛普拉斯的 CapSense 控制器解决方案 ...............................................................................................................91
4.1.1 CapSense Express 控制器（可配置解决方案） .....................................................................................91
4.1.2 CapSense 控制器（可编程解决方案） ...................................................................................................91
4.1.3 CapSense Plus（可编程解决方案）.......................................................................................................92
4.1.4 PSoC 与 CapSense ................................................................................................................................93
5. CapSense 选型指南......................................................................................................................................................94
5.1 选择正确的 CapSense 器件.................................................................................................................................94
6. CapSense 移植路径......................................................................................................................................................99
6.1 CY8C20XX6/H/AS 移植到 CY8C20XX7/S...........................................................................................................99
6.2 CY8C20X34 移植到 CY8C20XX6A/H/AS 或 CY8C20XX7/S ...............................................................................99
6.3 CY8C20XX6A/H/AS 或 CY8C20XX7/S 移植到 CY8C21X34/B / CY8C24X94 .....................................................99
6.4 引脚到引脚兼容性..............................................................................................................................................100
7. 资源 .............................................................................................................................................................................101
7.1 网站 ...................................................................................................................................................................101
7.2 器件特定的设计指南 ..........................................................................................................................................101
7.3 技术参考手册.....................................................................................................................................................101
7.4 开发套件............................................................................................................................................................102
7.4.1 通用 CapSense 控制器套件 ..................................................................................................................102
7.4.2 通用 CapSense 模块板 .........................................................................................................................102
7.4.3 CY8C201XX 的 CapSense Express 评估套件 ......................................................................................103
7.4.4 适用于 CY8CMBR2044 的 CapSense Express 评估套件......................................................................103
7.4.5 适用于 CY8CMBR3XXX 的 CapSense 评估套件 ..................................................................................103
目录
CapSense®入门 文档编号：001-91943 版本*A 6
7.4.6 接近感应评估套件.................................................................................................................................103
7.4.7 评估转接板............................................................................................................................................103
7.4.8 在线仿真（ICE）套件...........................................................................................................................103
7.4.9 PSoC 3 和 PSoC 5LP 开发套件 ............................................................................................................104
7.4.10 PSoC CapSense 扩展板套件................................................................................................................104
7.4.11 PSoC 4 开发套件 ..................................................................................................................................104
7.5 PSoC Designer..................................................................................................................................................104
7.6 PSoC Creator ....................................................................................................................................................105
7.7 PSoC Programmer ............................................................................................................................................106
7.8 I
2C 至 USB 桥接器套件 ......................................................................................................................................107
7.9 调试/数据查看工具.............................................................................................................................................107
7.10 桥接控制屏幕.....................................................................................................................................................108
7.10.1 MultiChart .............................................................................................................................................108
7.11 设计支持............................................................................................................................................................110
8. 附录 A：弹簧按键........................................................................................................................................................111
8.1 手指引起的电容 .................................................................................................................................................111
8.1.1 将弹簧安装到 PCB................................................................................................................................112
8.2 CapSense 和机械按键结合................................................................................................................................114
8.3 设计范例............................................................................................................................................................114
9. 附录 B：原理图和布局检查表......................................................................................................................................116
9.1 原理图检查表.....................................................................................................................................................116
9.1.1 去耦电容 ...............................................................................................................................................116
9.1.2 批量电容 ...............................................................................................................................................116
9.1.3 引脚分配 ...............................................................................................................................................116
9.1.4 CMOD .....................................................................................................................................................117
9.1.5 RB .........................................................................................................................................................117
9.1.6 CapSense 线路上的串联电阻 ...............................................................................................................117
9.1.7 通信线路上的串联电阻..........................................................................................................................117
9.2 布局检查表.........................................................................................................................................................118
9.2.1 按键 ......................................................................................................................................................119
9.2.2 滑条 ......................................................................................................................................................119
9.2.3 覆盖层...................................................................................................................................................120
9.2.4 传感器走线............................................................................................................................................120
9.2.5 传感器上的过孔.....................................................................................................................................120
9.2.6 接地层/网 ..............................................................................................................................................120
9.2.7 串联电阻 ...............................................................................................................................................121
9.2.8 屏蔽电极 ...............................................................................................................................................121
9.2.9 保护传感器............................................................................................................................................121