你好,
我一直在配置各种部件,其中三个LUT配置为逆变器,每个逆变器都连接到带有Schmitt触发输入和1x输出的引脚。
When I use these Schmitt inverters as oscillators in the well-known configuration (10K resistor from input to output, 100pf capacitor to ground on input) I
observe a lot of jitter, interaction between the oscillators and at high power supply voltages (>3v) instability (with a 20Mhz output). I have also tried
使用SLG46620。两个振荡器的问题较少,但甚至一个此表格的振荡器也具有抖动输出。
我遵循通常的解耦和屏蔽实践,并将结果与同一板代替CD40106。
电源轨和施密特输入之间是否存在内部串扰?当我选择2x输出时,这猜测来自观察,问题更差。
设备:
设备编号:
SLG46826
嗨Adrian,我们无法保证使用数字I / O的任何规范和用于生成某种模拟信号的块。有关详细数据,请参阅数据表。例如:传播延迟引脚与SHMITT的PIN数字输入以3.3V为1X推挽式,即使没有内部逻辑,也在上升至20MHz信号时段。您可以使用内环振荡器接收25MHz。至于串扰它可能是由PCB布局引起的,旁路电容放置得太远等。
谢谢。我的设计遵循Silego App建议的振荡器想法。Notes,其中数字元件用于产生模拟信号,尤其是使用3个引脚和低压数字输入选项的AN-CM-233和外部RC网络来制作刺穿振荡器。该设计是否也属于“无规格保证”量标?我试图仅使用两个引脚构建变量振荡器,因此我避免了特定的解决方案(因为它使用3个引脚总计),也不能使用固定的内置振荡器。Schmitt触发器的数据表规范对于DC阈值和滞后具有非常大的边缘 - 可能是因为温度和过程变化。没有动态规范,因此很难知道如何将抖动将被引入到通过Schmitt触发器(或此事项的其他输入)获取的信号中。这将适用于Schmitt触发器的更常见应用以及我正在尝试的振荡器雷竞技安卓下载。感谢对PIN /引脚延迟时间的分析。现在,了解高频反馈路径来自的位置是有趣的。 I have tried to eliminate all the pcb layout and bypass capacitors issues by battery powering and deadbug building over a groundplane. I am still leaning towards an internal crosstalk path, e.g., ground bounce or switching noise. It is also possible that there is a temporary current surge around the schmitt trigger generated by the two adjacent, non-schmitt trigger inputs handling slow moving signals. This would depend on whether the enable logic disables the input stage of those, the output stage or is done with pass transistors which I can't determine from the datasheet.
我刚刚发现了一个有点helpful warning against what I am attempting in AN-1150 "Note that the inverter component could have been implemented inside the GreenPAK5; however, significant coupling between the system’s input and output pins was observed, and so the capacitor voltage had to be buffered by an external inverter." I have seen this coupling wherever on the package I move the output pin so I would perhaps clarify that statement by saying "significant internal coupling between the system's input and output was observed". Presumably such coupling isn't present when analog comparators are used to make oscillators, the subject of several other app. notes. That points to the pin logic as the locus of the coupling as the comparators are part of the low voltage core powered by an internal regulator.
嗨Adrian,非常感谢您对我们产品的兴趣。雷电竞官网登录
您能否澄清您需要的数据究竟是什么?
SLG46620的输入电容会有所帮助。它们位于SLG46824的数据表上。
还有很大的别针电感,它用包装变化很多。这将有助于确定要使用哪个包(QFN或TSSOP)。这
这里讨论了http://www.ti.com/lit/an/szza038b/szza038b.pdf在第2.5.1节中。
VOLP(接地弹跳)为1x 2x和4倍输出,在各种电源值和负载条件下。
一致的指导原则,以使用低压数字输入/常规数字输入/施密电路输入/比较器输入模式获取外部信号(数字或模拟)时最小化抖动。正如我所提到的,各种应用笔记中都有挑战,但也许我错过了一些有用的指导方针。
嗨阿德里安,
我用我的管理说过话,我们没有可用于定义和描述您所要求的附加数据表参数的必要资源。
您可能会假设同一包装在其引脚上具有相似的电容/电感范围。谢谢。
谢谢你的提示response. I can move on to my next project now.