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PSoC™ 4 Forum Discussions

YuMa_1534086
Level 6
Level 6
10 likes received 100 solutions authored 50 solutions authored

Hello

Q1)

Could you please let us know solution in case diff count with finger-touch saturated because sensitivity is too high.

I think that there are the following methods.

Please check whether they are correct or not.

And could you please let us know if there are other solutions.

-----------------------------------------------------------------------------------------------------------

[IC tuning]

- Decreased calibration target        (increased IDAC value)

- Disabled compensation IDAC      (increased CP => increased IDAC)

- Disabled shield                             (increased CP => increased IDAC)

[Hardware]

- Increased CP                                (increased IDAC value)

- Changed overlay                          (decreased sensitivity)

-----------------------------------------------------------------------------------------------------------

Q2)

Could you please let us know solution in case IDAC saturated

I think that there are the following methods.

Please check whether they are correct or not.

And could you please let us know if there are other solutions.

-----------------------------------------------------------------------------------------------------------

[IC tuning]

- Increased calibration target          (decreased IDAC value)

- Enabled compensation IDAC       (Increased IDAC drive ability)

- Enabled shield                              (decreased CP => decreased IDAC)

- “Inactive sensor connection” changes from GND to shield.  (decreased CP => decreased IDAC)

[Hardware]

- Decreased CP                              (decreased IDAC value)

- mesh pattern changes from GND to shield (decreased CP => decreased IDAC)

-----------------------------------------------------------------------------------------------------------

Best Regards.

Matsubara

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1 Solution
RyanZhao
Moderator
Moderator
Moderator
750 replies posted 100 sign-ins 100 likes received

Hello Matsubara-san,

Comments below are FYI.

Q1)

Solution in case diff count with finger-touch saturated because sensitivity is too high.

-----------------------------------------------------------------------------------------------------------

[IC tuning]

- Decreased calibration target        (increased IDAC value)                           - Correct

- Disabled compensation IDAC      (increased CP => increased IDAC)         - Correct, but CP not increased. Software changing will not change CP.  See Figure 5-12 in AN85951(https://www.cypress.com/documentation/application-notes/an85951-psoc-4-and-psoc-6-mcu-capsense-desig... )

- Disabled shield                             (increased CP => increased IDAC)         - Correct, at the same time, it is better to connect mesh pattern with GND. If leave them float, CP will not be increased effectively.

[Hardware]

- Increased CP                                (increased IDAC value)                            - Correct

- Changed overlay                          (decreased sensitivity)                              - Correct

-----------------------------------------------------------------------------------------------------------

Increasing CP or decreassing sensitivity(CF) is the best choice to solve diffcount saturated.

Q2)

Solution in case IDAC saturated

-----------------------------------------------------------------------------------------------------------

[IC tuning]

- Increased calibration target          (decreased IDAC value)                                                                   - Correct

- Enabled compensation IDAC       (Increased IDAC drive ability)                                                           - Correct

- Enabled shield                              (decreased CP => decreased IDAC)                                                - Correct

- “Inactive sensor connection” changes from GND to shield.  (decreased CP => decreased IDAC)       - Correct

[Hardware]

- Decreased CP                              (decreased IDAC value)                                                                    - Correct

- mesh pattern changes from GND to shield (decreased CP => decreased IDAC)                                  - Correct

-----------------------------------------------------------------------------------------------------------

Thanks,

Ryan

View solution in original post

0 Likes
2 Replies
RyanZhao
Moderator
Moderator
Moderator
750 replies posted 100 sign-ins 100 likes received

Hello Matsubara-san,

Comments below are FYI.

Q1)

Solution in case diff count with finger-touch saturated because sensitivity is too high.

-----------------------------------------------------------------------------------------------------------

[IC tuning]

- Decreased calibration target        (increased IDAC value)                           - Correct

- Disabled compensation IDAC      (increased CP => increased IDAC)         - Correct, but CP not increased. Software changing will not change CP.  See Figure 5-12 in AN85951(https://www.cypress.com/documentation/application-notes/an85951-psoc-4-and-psoc-6-mcu-capsense-desig... )

- Disabled shield                             (increased CP => increased IDAC)         - Correct, at the same time, it is better to connect mesh pattern with GND. If leave them float, CP will not be increased effectively.

[Hardware]

- Increased CP                                (increased IDAC value)                            - Correct

- Changed overlay                          (decreased sensitivity)                              - Correct

-----------------------------------------------------------------------------------------------------------

Increasing CP or decreassing sensitivity(CF) is the best choice to solve diffcount saturated.

Q2)

Solution in case IDAC saturated

-----------------------------------------------------------------------------------------------------------

[IC tuning]

- Increased calibration target          (decreased IDAC value)                                                                   - Correct

- Enabled compensation IDAC       (Increased IDAC drive ability)                                                           - Correct

- Enabled shield                              (decreased CP => decreased IDAC)                                                - Correct

- “Inactive sensor connection” changes from GND to shield.  (decreased CP => decreased IDAC)       - Correct

[Hardware]

- Decreased CP                              (decreased IDAC value)                                                                    - Correct

- mesh pattern changes from GND to shield (decreased CP => decreased IDAC)                                  - Correct

-----------------------------------------------------------------------------------------------------------

Thanks,

Ryan

0 Likes

Ryan-san.

Thank you for your support.

I understand.

Best Regards.

Matsubara

0 Likes