关于MBR信号电平和串联电阻

你好。
Q1）
下面是“开始使用CAPSENSE”的描述（AN648 46）。
下列内容也适用于MBR3吗？
换句话说，如果串联电阻从560OHM增加，那么MBR3信号电平会降低吗？
但是MBR3调谐模式是智能的。
Struts通过MBR3本身自动调整FSW等参数。
由于参数自动调节，即使串联电阻增加，用户也不会感觉到太多的灵敏度降低吗？
我认为，MBR3可以驱动足够的传感器垫，如果MBR3使用较慢的FSW通过自动调谐，即使串联电阻变得更大。
在这个时候，我认为信号电平不会变得更低。
文档描述
事业单位
如果串联电阻值设置为高，则开关 电路的较慢时间常数抑制发射，但限制其可转移的电荷量。
因此，传感器可能不会完全充电和放电。
这降低了信号电平，这又降低了信噪比。
较小的值更好，但在阻止RF发射和干扰方面效率较低。
事业单位
Q2）
下面是“开始使用CAPSENSE”的描述（AN648 46）。
下列内容也适用于MBR3吗？
你能告诉我们MBR3推荐的系列电阻（最小/最大）吗？
560欧姆到4.7kOHm？
文档描述
事业单位
一般铜板 PCBs输入线的推荐串联电阻为560Ω。
ITO面板已经提供了一个高抗；一个可能没有在价值选择太多的灵活性（100Ω–1 KΩ）。
串联电阻通常用在560Ω–4.7 K的范围Ω电磁兼容的目的。
该系列电阻可以用实际的最大值从设备到设备的变化。
这取决于诸如作为传感器的GPIO性多因素，开关频率用于扫描传感器，和信噪比的要求。
事业单位
Q3）
MBR3什么时候决定Fsw？
MBR3是否决定每个扫描定时的FSW？
（MBR3 FSW从扫描改变为扫描。MBR3 FSW不是恒定值。
还是MBR3在上电或复位时决定FSW？
（因此，MBR3 FSW是恒定值，直到上电或复位）
最好的问候。
松塔



以下为原文
Hello.


Q1)
Below is description of “Getting Started with CapSense”(AN64846).
Do the following contents also apply to MBR3?

In other words, does MBR3 signal level become lower if series resistance increased from 560ohm?

But MBR3 tuning mode is smartsense.
Smartsense automatically tunes parameters such as Fsw etc by MBR3 itself.
Since parameters are auto-tuned, will not user feel too much sensitivity reduction even if series resistance increased?
I think that MBR3 can drive enough sensor-pad if MBR3 uses slower Fsw by auto-tuning even if series resistance becomes bigger.
In this time, I think that signal level does not become lower.

Document description
==========================================
If the series resistance value is set high, the slower time constant of the switching circuit suppresses the emission but limits the amount of charge that it can transfer.
Thus the sensors may not get charged and discharged completely.
This lowers the signal level, which in turn lowers the SNR.
Smaller values are better, but are less effective at blocking RF emissions and interference.
==========================================


Q2)
Below is description of “Getting Started with CapSense”(AN64846).
Do the following contents also apply to MBR3?

Could you please let us know recommended series resistance(min/max) of MBR3?
560ohm to 4.7kohm?

Document description
==========================================
The recommended series resistance for CapSense input lines on general copper PCBs is 560 Ω.
An ITO panel already provides a high resistance; one may not have too much flexibility in the value selection (range 100 Ω–1 kΩ).
Series resistors are generally used in the range of 560 Ω–4.7 kΩ for EMC purpose.
The actual maximum value of the series resistor that can be used varies from device to device.
This depends on multiple factors such as the resistance of the GPIO used as sensor, the switching frequency used to scan sensors, and the SNR required.
==========================================


Q3)
When does MBR3 decide Fsw?

Does MBR3 decide Fsw every scan timing?
(So MBR3 Fsw changes from scan to scan. MBR3 Fsw is not constant value.)

Or does MBR3 decide Fsw when power-up or reset?
(So MBR3 Fsw is constant value until power-up or reset)


Best Regards.
Yutaka Matsubara