How to further improve proximity sensitivity

Tip / Sign in to post questions, reply, level up, and achieve exciting badges. Know more

cross mob
YuMa_1534086
Level 7
Level 7
Distributor - Macnica (Japan)
500 replies posted 250 sign-ins 10 likes received

Hello.

I would like to know how to further improve proximity sensitivity.

But I already use settings to achieve high sensitivity.

CSD component version is 6.0.

=================================

Scan resolution is 16bit.

Sense clock is 6000kHz.(Most high setting)

Enabled compensation IDAC and shield.

Enabled all filters(IIR, median, average)

=================================

Is there any other way to further increase sensitivity other than changing HW layout?

For example, increase calibration target etc.

Best Regards.

Yutaka Matsubara

0 Likes
1 Solution
Hari
Moderator
Moderator
Moderator
750 replies posted 500 replies posted 250 solutions authored

Hi YuMa_1534086

The easiest way is to probe the CapSense pin and check if the sensors are charged and discharged completely.

pastedImage_0.png  

Figure 1: Incomplete charging and discharging of sensor

pastedImage_1.png  

Figure 2: Complete charging and discharging of sensor

When a sensor is not charging and discharging completely, sensitivity will be poor and will also lead to inaccurate results.

Yes. the sensitivity will be better when the sense clock frequency is correctly chosen.

Thanks and regards

Harigovind

View solution in original post

0 Likes
4 Replies
Hari
Moderator
Moderator
Moderator
750 replies posted 500 replies posted 250 solutions authored

Hello YuMa_1534086

In CapSense 6.0 these are the ways to increase sensitivity of proximity sensor. While setting the highest sense clock frequency, please make sure that the proximity sensor is charging and discharging completely.

Please let me know the diagonal distance of the proximity loop that you are using and the required sensing distance for your application.

Thanks and regards

Harigovind

0 Likes
YuMa_1534086
Level 7
Level 7
Distributor - Macnica (Japan)
500 replies posted 250 sign-ins 10 likes received

Dear Harigovind-san.

Thank you for your reply.

>>>While setting the highest sense clock frequency, please make sure that the proximity sensor is charging and discharging completely.

How should we judge whether proximity sensor is charging and discharging completely or not?

When sensor is not charging and discharging completely at 6000kHz, dose sensitivity improve if sense clock frequency is lowered(6000KHz -> 3000kHz)?

Best Regards.

Yutaka Matsubara

0 Likes
Hari
Moderator
Moderator
Moderator
750 replies posted 500 replies posted 250 solutions authored

Hi YuMa_1534086

The easiest way is to probe the CapSense pin and check if the sensors are charged and discharged completely.

pastedImage_0.png  

Figure 1: Incomplete charging and discharging of sensor

pastedImage_1.png  

Figure 2: Complete charging and discharging of sensor

When a sensor is not charging and discharging completely, sensitivity will be poor and will also lead to inaccurate results.

Yes. the sensitivity will be better when the sense clock frequency is correctly chosen.

Thanks and regards

Harigovind

0 Likes
YuMa_1534086
Level 7
Level 7
Distributor - Macnica (Japan)
500 replies posted 250 sign-ins 10 likes received

Dear Harigovind-san.

Thank you for your support.

I understand.

Best Regards.

Yutaka Matsubara

0 Likes