你好，
我有一个应用程序，使用DA14585受到极端EMI。我认为这是扰乱高频振荡器，并使微控制器不会在情况下运行或不断复位。是否有可能用MEMS振荡器替换16MHz晶体以改善这一点？
The data sheet only lists a minimum and typical external clock voltage of 1 and 1.2V, respectively, but no maximum voltage.这个振荡器会工作吗？？
Thank you!
Keywords:
Device:
Hi ahiggs,
Thanks for your question and for your interest in our BLE solutions. Let me check it and I’ll get back to you.
谢谢，PM_DIALOG.
Hi ahiggs,
尽管使用外部振荡器存在一些缺点（例如，功耗，相位噪声，成本..），但DA14585可以处理外部16MHz时钟。振荡器的输出电压应分为1.2V。
另一方面，如果EMI是这里的问题，那么某种屏蔽不会做更好的工作吗？
谢谢，PM_DIALOG.
嗨，谢谢你的回应。我们已经使用了PCB安装屏蔽，但环境足够苛刻，这是不够的。我可以上传PCB的图像，在那里您可以看到屏蔽和常规布局的寄存器如果如果有帮助，那么如果有帮助。
Hi ahiggs,
是的，请上传PCB的图像。这会有所帮助。
谢谢，PM_DIALOG.
你好，
Here is a PDF of the layout. The device is powered by a small 3.6V rechargable battery for measuring a thermocouple in a high voltage environment with extreme EMI.
Hi ahiggs,
我们有布局审查，XTAL的接地看起来不寻常。我们将XTAL周围的地环与顶层接地结合起来。所以我们没有标有绿色箭头的空间 - 请参阅附件。
谢谢，PM_DIALOG.
你好，
I have tested boards with both ground designs as I have encountered advice both for and against the grounding ring. We did not notice a difference in performance in the harsh environment between the two.
Do you have suggestions of what to do with unused GPIO and LFxtal pins?
Thanks,
Ansel.
Hi ahiggs,
您能否回答以下问题？
The default setting for all GPIOs is input pull down. Only P0_0 is used in this application. There are no traces at the other GPIOs or the LF xtal. We would say it is quite unlikely, that those pins contribute to the issue.
这是你的最终布局吗？如果没有，请在准备就绪时使用确切的信息上传最终布局。
谢谢，PM_DIALOG.
1. I do not know for certain that the oscillator is causing issues. The code running on the 14585 is based off the DSPS example and periodically samples an ADC (via the easy_timer) and notifies a receiver with the value, it has been well tested on this project and others and has never encountered issues. (answered further in 5.)
2。这个水晶。16MHz, 18pF, 80ohm, 30ppm。Has been used on other 14585 designs without issue (standard industrial environment)
3.屏蔽不会将迹线覆盖到天线？我不认为这是必要的，因为它是被地面平面敏感的。
4. This desgn is used for laboratory testing with close proximity of transmitter and receiver and does not require exceptional performance to warrant the cost of impedance control or measurement.
该委员会在非EMI环境中工作，并具有中度EMI。连接到P0_0的放大器测量具有快速变化的共模电压的差分热电偶信号。当CMV在0到10kV之间发生变化时，14585的函数按预期函数，可连接并输出正确的数据。如果CMV更改〜10kV，则14585将停止广告，广告但不发送任何通知，或广告，但是直接从接收器断开重新连接 - 在EMI清除直到EMI。CMV迅速增加并减少，每微秒速率的多kV速率，并且发生在大约15Hz。
我不知道精确的频率或力量。我相信在子GHz范围内很好，但我们没有设备测量它。
This is the most recent layout. As this is not a design for series production, we are able to relatively quickly make changes and test new layouts.
Thanks!
Ansel.
Hi ahiggs,
16MHz Xtal不适合我们的规范。
The load capacitance should be 10pF and the 80Ohm ESR is only valid for xtals with a frequency between 20MHz and 29.9MHz. The 16MHz xtal has an ESR of 150Ohm, which is too high for our oscillator.
在尝试MEMS振荡器之前，更改为XTAL，以满足我们的规范将是一个选项。
你能修剪18pf xtal到16MHz吗？
Please also check theAN-B-054：DA14585 / 586应用硬件设计指南。
谢谢，PM_DIALOG.
好的，哇，我完全忽略了，而Digikey的抵抗价值不正确也没有帮助。这个水晶appears to be more suitable。I will look at changing it when we next revise the boards.
当14585在以前的设计中，我没有尝试修剪水晶。
Thanks!
Hi ahiggs,
I’ve checked the datasheet and the load capacitance is 8pF. This should be 10pF.
谢谢，PM_DIALOG.
你好，
除非我错了，否则数据表表示部件号ECS-160-10.-36q-aes-tr表示电容应该10 pfthis version. Otherwise the resistance, shunt capacitance, and tolerance are all within the reccomended range?
Thanks!
Hi ahiggs,
我的道歉 - 是的负载电容在零件号中编码。ECS-160-10-36Q XTAL确实具有10PF的负载电容。
频率公差几乎没有，但如果您在全温度范围内没有使用它，您将修剪16MHz振荡器。在这种情况下，XTAL将适合。
谢谢，PM_DIALOG.