由内至外分析晶振停振的原因

shuszhao

<span .="color: rgb(66, 66, 66); font-family: "Open Sans"; font-size: 16px; background-color: rgb(255, 255, 255);" style="word-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(100, 100, 100); font-family: myFont, "Microsoft YaHei"; font-size: 16px; text-align: justify; background-color: rgb(255, 255, 255);">有许多工程师在遇到,晶振在电路板,一会儿起振,一会儿不起振,或用电吹风吹一下又可以正常工作等问题。<span .="box-sizing: border-box; color: rgb(66, 66, 66); font-family: "Open Sans"; font-size: 16px; letter-spacing: 0px; background-color: rgb(255, 255, 255); margin: 0px; padding: 0px; max-width: 100%; word-wrap: break-word !important;" style="word-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(100, 100, 100); font-family: myFont, "Microsoft YaHei"; font-size: 16px; text-align: justify; background-color: rgb(255, 255, 255);">这个时候就开始怀疑是否是晶振出问题了,其实我们不能下太早结论，必须抓到问题核心，才能做出正确判断。<span .="box-sizing: border-box; color: rgb(66, 66, 66); font-family: "Open Sans"; font-size: 16px; letter-spacing: 0px; background-color: rgb(255, 255, 255); margin: 0px; padding: 0px; max-width: 100%; word-wrap: break-word !important;" style="word-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box;">

                               
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<p .="box-sizing: border-box; margin: 0px; padding: 0px; max-width: 100%; clear: both; min-height: 1em; word-wrap: break-word !important;" style="word-wrap: break-word; margin-bottom: 10px; padding: 0px; box-sizing: border-box;">       唯物辩证法指的是一种研究自然、社会、历史和思维的哲学方法。其实就是告诉我们在遇到事情是要以一分<span .="box-sizing: border-box; margin: 0px; padding: 0px; max-width: 100%; letter-spacing: 0px; word-wrap: break-word !important;" style="word-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box;">为二，对于晶振也不例外，应从内外因不同的角度来分析晶振停振。下面我们以内外因来分析晶振停振：<p .="box-sizing: border-box; margin: 0px; padding: 0px; max-width: 100%; clear: both; min-height: 1em; word-wrap: break-word !important;" style="word-wrap: break-word; margin-bottom: 10px; padding: 0px; box-sizing: border-box;">       1、排除外界元件不良的情况，因为外界零件无非为电阻、电容，让你很容易鉴别是否为不良品。<p .="box-sizing: border-box; margin: 0px; padding: 0px; max-width: 100%; clear: both; min-height: 1em; word-wrap: break-word !important;" style="word-wrap: break-word; margin-bottom: 10px; padding: 0px; box-sizing: border-box;">　　2、排除晶振为不起振品的可能性，这里你不会只试了1~2个晶振就停止了测试。<p .="box-sizing: border-box; margin: 0px; padding: 0px; max-width: 100%; clear: both; min-height: 1em; word-wrap: break-word !important;" style="word-wrap: break-word; margin-bottom: 10px; padding: 0px; box-sizing: border-box;">　　3、排除线路错误的可能性，这样先试着用相应型号线路的推荐电路进行比较。<p .="box-sizing: border-box; margin: 0px; padding: 0px; max-width: 100%; clear: both; min-height: 1em; word-wrap: break-word !important;" style="word-wrap: break-word; margin-bottom: 10px; padding: 0px; box-sizing: border-box;">　　4、可以改变晶体两端的电容，没准晶振就能正常工作了，电容的大小请参考晶振的使用说明，相匹配的电容<span .="box-sizing: border-box; margin: 0px; padding: 0px; max-width: 100%; letter-spacing: 0px; word-wrap: break-word !important;" style="word-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box;">很重要。<p .="box-sizing: border-box; margin: 0px; padding: 0px; max-width: 100%; clear: both; min-height: 1em; word-wrap: break-word !important;" style="word-wrap: break-word; margin-bottom: 10px; padding: 0px; box-sizing: border-box;"><span .="box-sizing: border-box; margin: 0px; padding: 0px; max-width: 100%; letter-spacing: 0px; word-wrap: break-word !important;" style="word-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box;">

                               
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<p .="box-sizing: border-box; margin: 0px; padding: 0px; max-width: 100%; clear: both; min-height: 1em; word-wrap: break-word !important;" style="word-wrap: break-word; margin-bottom: 10px; padding: 0px; box-sizing: border-box;">       晶振本身的原因，晶片碎裂、阻抗过大、频率不良、晶体牵引力不足过大寄生反应。或在电路上，负载电容<span .="box-sizing: border-box; margin: 0px; padding: 0px; max-width: 100%; letter-spacing: 0px; word-wrap: break-word !important;" style="word-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box;">或电路设计或加工造成的杂散电容离散度大，晶体两端电压不足，这些也会导致晶振停振！<p .="box-sizing: border-box; margin: 0px; padding: 0px; max-width: 100%; clear: both; min-height: 1em; word-wrap: break-word !important;" style="word-wrap: break-word; margin-bottom: 10px; padding: 0px; box-sizing: border-box;">       如果遇到这种问题，首先要检测晶振的频率参数和晶振的电阻是不是在要求的范围内，如果是在要求的范围<span .="box-sizing: border-box; margin: 0px; padding: 0px; max-width: 100%; letter-spacing: 0px; word-wrap: break-word !important;" style="word-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box;">内;其次要检查晶振的焊接温度会不会高，造成晶振的第二次损坏，一般要求焊接的温度是在250度左右或更低，<span .="box-sizing: border-box; margin: 0px; padding: 0px; max-width: 100%; letter-spacing: 0px; word-wrap: break-word !important;" style="word-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box;">最高不要超过300度。如果这些都是在要求的范围内，那就要考虑是不是整个单片机电路的问题了。<p .="box-sizing: border-box; margin: 0px; padding: 0px; max-width: 100%; clear: both; min-height: 1em; word-wrap: break-word !important;" style="word-wrap: break-word; margin-bottom: 10px; padding: 0px; box-sizing: border-box;">       检测晶振参数和调整焊接温度可以很容易做到，如果单片机电路的问题可以找方案商来解决，再则是看晶振<span .="box-sizing: border-box; margin: 0px; padding: 0px; max-width: 100%; letter-spacing: 0px; word-wrap: break-word !important;" style="word-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box;">有没有漏气，晶振在潮湿的天气情况下也会出现这种问题，这样就建议更换质量较好的晶振。

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