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李永清

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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

以上来自于百度翻译


     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

回帖(11)

王华梅

2018-9-10 15:25:22
你好,
“开始使用CAPSENSE(AN648 46)”也适用于MBR3设备。
1。SrimeSnices根据时间常数(RC)调整感测频率(FSW)。因此,信号(原始计数)会减少。
如果你的应用需要更高的电阻来使用(560欧姆),我建议你检查SNR & GT;5:1,并确保传感器完全充电和放电。
2。推荐的串联电阻为560Ω。但电阻范围为560~4.7 K。
三。FSW是在加电或重置期间设置的恒定值。
希望这有帮助。
谢谢,
布雷加德什

以上来自于百度翻译


     以下为原文
  Hi,
 
The "Getting Started with CapSense (AN64846)" applies to the MBR3 devices also.
 
1. The SmartSense adjusts the Sense frequency (Fsw) in accordance to the time constant (RC). So, the signal (raw counts) would get reduced.
 
If your application requires a higher resistance to be used (> 560 ohm), I would recommend you to check if SNR > 5:1 and ensure that the sensors are completely charged and discharged.
 
 
 
 
2. The recommended series resistance is 560 Ω. However, the resistance range could be from 560Ω to 4.7 k .
 
3. Fsw is a constant value that is set during the power up or reset.
 
Hope this helps.
 
Thanks,
Bragadeesh
 
 
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李永清

2018-9-10 15:31:02
引用: 60user152 发表于 2018-9-10 07:00
你好,
“开始使用CAPSENSE(AN648 46)”也适用于MBR3设备。
1。SrimeSnices根据时间常数(RC)调整感测频率(FSW)。因此,信号(原始计数)会减少。

亲爱的BrAGADEESSAN。
谢谢你的回答。
你能告诉我们MBR3能选择的所有FSW设置值吗?
最好的问候。
松塔

以上来自于百度翻译


     以下为原文
  
Dear Bragadeesh-san.

 

Thank you for your answer.

 

Could you please let us know all Fsw setting value that MBR3 can select?

 

Best Regards.

Yutaka Matsubara
举报

王华梅

2018-9-10 15:40:29
引用: 535夏花 发表于 2018-9-10 07:06
亲爱的BrAGADEESSAN。
谢谢你的回答。
你能告诉我们MBR3能选择的所有FSW设置值吗?

你好,
检测频率可以从45 kHz到12000 kHz。
当做,
布雷加德什

以上来自于百度翻译


     以下为原文
  Hi,
 
The Sense frequency can be from 45 kHz to 12000 kHz.
 
Regards,
Bragadeesh
举报

李永清

2018-9-10 15:47:30
引用: 60user152 发表于 2018-9-10 07:15
你好,
检测频率可以从45 kHz到12000 kHz。
当做,

亲爱的BrAGADEESSAN。
Q1)
马克斯系列电阻值为4.7kOHm。
您能告诉我们为什么柏树指定4.7kOHm为最大值吗?
你能告诉我们确定最大值的标准吗?
Q2)
如果串联电阻大于4.7kOHm,IC行为将变成什么?
出现什么样的问题?
最好的问候。
松塔

以上来自于百度翻译


     以下为原文
  Dear Bragadeesh-san.
 
Q1)
Max series resistance value is 4.7kohm.
Could you please let us know why cypress specified 4.7kohm as max value?
Could you please let us know a criteria for determining max value?
 
Q2)
If series resistance becomes more than 4.7kohm, what will become of IC behavior?
What kind of problems occurs?
 
 
Best Regards.
Yutaka Matsubara
举报

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