晶振是单片机电路中必不可少的原件,只有有了晶振才能让单片机有条不紊地工作,因此在这记录下晶振的工作原理。
- 晶振的外观
![7f041023b6f843ccb637e465ee773d9e?from=pc.jpg 7f041023b6f843ccb637e465ee773d9e?from=pc.jpg](https://static.assets-stash.eet-china.com/forum/202204/22/154814d20993rvrp9rd023.jpg)
2.晶振结构
当覆银层(引脚)加上电压后,石英晶体会产生变形从而产生电压,因此不断给晶体施加交变电压(正弦波)就能得到稳定的振动频率,从而得到稳定的频率信号。
3.原理分析
利用石英晶体的压电效应,得到稳定的频率
![beabf03f79e845638c06456dad9d4c27?from=pc.jpg beabf03f79e845638c06456dad9d4c27?from=pc.jpg](https://static.assets-stash.eet-china.com/forum/202204/22/154814szaqo9udfblbqlur.jpg)
4.晶振电路
![225b76bdd6a446f0a9b55f6a5c8369dc?from=pc.jpg 225b76bdd6a446f0a9b55f6a5c8369dc?from=pc.jpg](https://static.assets-stash.eet-china.com/forum/202204/22/154814zg3t5igdtq4yvs1q.jpg)
当输入信号频率等于谐振频率时,LRC串联阻抗相当于 0 (串联谐振) ,
![a2ff42570b854b6b970fb7e75631139c?from=pc.jpg a2ff42570b854b6b970fb7e75631139c?from=pc.jpg](https://static.assets-stash.eet-china.com/forum/202204/22/154814kwu2aa1wuwiop1b1.jpg)
此时(发生串联谐振时) 整体阻抗很小,
![635ade028b704126bb8d18ed55ca37ee?from=pc.jpg 635ade028b704126bb8d18ed55ca37ee?from=pc.jpg](https://static.assets-stash.eet-china.com/forum/202204/22/154814calca5dzad7dp1am.jpg)
5.谐振电路与晶振
谐振电路与晶振同样能产生谐振,为什么不能互相替代呢?这是因为谐振电路的品质因数只有几百,而晶振的品质因数高达百万。(品质因数越大效果越好)
![0cf920dcec64466ab58714ea888b3960?from=pc.jpg 0cf920dcec64466ab58714ea888b3960?from=pc.jpg](https://static.assets-stash.eet-china.com/forum/202204/22/154814o2lzjyxk2kchzlf2.jpg)
6.如何给晶振提供交变电压
利用电路刚上电时会有大量噪声的特性,
![ea2a5c2a727d4f14923d8174c377d1d5?from=pc.jpg ea2a5c2a727d4f14923d8174c377d1d5?from=pc.jpg](https://static.assets-stash.eet-china.com/forum/202204/22/154814hl1n012x4bgn72kn.jpg)
![2a65db2ef4e84bccbd57a723b95b38a5?from=pc.jpg 2a65db2ef4e84bccbd57a723b95b38a5?from=pc.jpg](https://static.assets-stash.eet-china.com/forum/202204/22/154814qh59q1hhirih99uf.jpg)
![3c319f2aae21445e99903b1ca3c5a058?from=pc.jpg 3c319f2aae21445e99903b1ca3c5a058?from=pc.jpg](https://static.assets-stash.eet-china.com/forum/202204/22/154814nvvbvnn75oobx2bx.jpg)
7.有源晶振
![e70f795416664f119fc745286458c31d?from=pc.jpg e70f795416664f119fc745286458c31d?from=pc.jpg](https://static.assets-stash.eet-china.com/forum/202204/22/154814roqnp9gwjq51wpjn.jpg)
8.常用晶振频率
![12e9a8865d3e4e089ca95024887cbf1c?from=pc.jpg 12e9a8865d3e4e089ca95024887cbf1c?from=pc.jpg](https://static.assets-stash.eet-china.com/forum/202204/22/154814s70rlyrgm7f1gj1x.jpg)
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