• State Resolved
  • Locked Locked
  • Replies 5 replies
  • Subscribers 46 subscribers
  • Views 2938 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TSC2007 PENIRQ problem

Takumi Suzuki1
Mastermind 8420 points
Other Parts Discussed in Thread: TSC2007, TSC2017, TSC2003

Hi,

I would like to ask you a question about PENIRQ of TSC2007.

My customer has been evaluationg TSC2007 and found the problem with PENIRQ behavior.

Q) After power-on, following phenomenon has happened.

    The PENIRQ signal status keeps "LOW" level under any conditon of X+ (High/Low).

    This phenomenon seems to have happened easily on higher temperature. (around 60℃)

Sorry I have not confirmed TSC2007 POR condition of the customer circuits.

But can I understand that this phenomenon is due to POR issue?

Could you tell me any other possible root cause if you know?

Why is it easily happend under high temperature?

 

Probably in case of using TSC2017, such kind of phenomenon will not appear in same customer circuits.

Is it possible to replace TSC2007 to TSC2017?

 

Thank you very much in advance.

Best Regards,

 

  • 0
    TI__Guru 52115 points

    Hi Takumi,

    See my comments below:

    a) The POR issue is the most common issue for TSC2007. For more information, please refer to the app note: www.ti.com/.../sbaa161.pdf

    b) Yes. TSC2017 is compatible with TSC2003/TSC2007. In addition, TSC2017 has a dedicated reset pin, which offers a much more robust reset function than TSC2007.  If you want to replace the TSC2007 with TSC2017, the only problem is that TSC2017 is available in DSBGA package.

    Andy

  • 0 in reply to Andy Liu (BMS)
    Mastermind 8420 points
    Hello Andy-san,

    Thank you very much for your reply.

    I visited the customer to confirm the phenomenon for sure.
    The phenomenon is as following.

    - The POR specification of the customer meets data sheet spec. (datasheet P31)
    - Around over 60℃, PENIRQ has fixed to low level after POR.
    - PENIRQ has fixed to low level when the temperature is over around 60℃.
    In this case, TSC2007 is working normally from 25℃ to 60℃.
    25℃　working well ---- temperature up ---- get to 60℃ then PENIRQ is fixed to low
    - Once PENIRQ is fixed to low, the situation is not changed though decreasing temperature till 25℃.
    Only by POR, TSC2007 can get back to normal situation.
    - Although under PENIRQ is low fixed, TSC2007 can accept I2C command from Host, that is to say, Read/Write is OK.
    It's very strange.
    - The customer made 6 trial boards and the phenomenon has happened on 3 boards.
    About normal 3 boards, the phenomenon has not happned at 85℃.

    Could you please consider this phenomenon and advise me anything you notice?

    And can I ask you 2 more questions about the specification of TSC2007?

    Q1) Data sheet P24, table 2 D3-D2 Bit : "00 Power down between cycles"
    What is the meaning of "Between Cycles"?
    What is the condition of "Power Down"?
    How does TSC2007 come back to normal mode from power down?
    When TSC2007 come back to normal, "internal reset"(not POR) has happened?

    Q2) Data sheet P3, Switch drivers drive current 100mS duration/50mA
    About the duration, 100ms is max?
    In case of under 50mA , how long is the max duratrion?
    For example, 25mA ---- 200mSec?

    Thank you for your support!
    Regards,
  • 0 in reply to Takumi Suzuki1
    TI__Guru 52115 points
    Hi Takumi,

    Below are my comments:
    a) Could you please consider this phenomenon and advise me anything you notice?
    Comment : If a real POR issue occurs, usually the i2c communication between the TSC2007 and the host will fail. I'm not 100% sure that we are dealing with a POR issue since you mentioned that the i2c read/write was OK. Could you find any i2c communication issue when this issue occurs?

    b) Data sheet P24, table 2 D3-D2 Bit : "00 Power down between cycles"
    What is the meaning of "Between Cycles"?
    What is the condition of "Power Down"?
    Comment : The TSC2007 is a command based touch controller, which means the ADC conversion is controller by the host as well. I think "Power down between cycles" means that the internal ADC is powered down to save power after a previous ADC conversion is done and before the next ADC conversion occurs again.

    c) How does TSC2007 come back to normal mode from power down?
    Comment : You can just send some command via i2c to force the TSC2007 to enable its ADC again.

    d) When TSC2007 come back to normal, "internal reset"(not POR) has happened?
    Comment: I don't have the details on the "internal reset" you are referring to. In my opinion, some very basic initialization could happen if the ADC is enabled again.

    e) Data sheet P3, Switch drivers drive current 100mS duration/50mA
    Comment: I think that the "100ms duration" is a test condition. It doesn't necessarily mean that 100ms is the max.

    Andy
  • 0 in reply to Andy Liu (BMS)
    Mastermind 8420 points

    Hi Andy-san,

    Thank you for you reply!

    According to the customer, all I2C communication is enable.

    Only PENIRQ is fixed to low level around over 60℃ without PEN-touch.

    Once PENIRQ is fixed to low level, this situation is not changed untill POR is issued at room temperature.

    Under this situation, all I2C communication is enable...

    Have you ever experianced this kind of situation?

    The devices have something bugs??

    Best Regards,

     

  • 0 in reply to Takumi Suzuki1
    Mastermind 8420 points

    Hi Andy-san,

    The customer is considerign to use TSC2017 instead of TSC2007 due to TSC2017 has reset sequence.

    So could you please provide me "POR" reference circuits to meet TSC2017 POR specifications(datasheet P32) as soon as possible?

    Thank you for your kind support!

    Best Regards,