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TUSB4041I: EEPROM Access

Prodigy 145 points

Replies: 27

Views: 246

Part Number: TUSB4041I

Hey there, we are using the TUSB4041I in a design that requires us to use the EEPROM. Can you please provide the programming tool?

Best regards,

Sebastian.

  • Hi Sebastian,

    Please accept my friend request so that I may send you the software. Please update the thread once you have accepted the request. 

  • In reply to Malik Barton57:

    Hey Malik, I had accepted your friend request this morning but just now realized you asked me to update the thread afterwards... so here we go.

  • In reply to Sebastian Wegner:

    Hi Sebastian,

    The software has been sent. Please post here if you have any issue or questions. 

  • In reply to Malik Barton57:

    Hey Malik,

    Thanks again for sending the software.

    We still have issues with the TUSB4041I. The drivers and the programming software seem to work as far as we get, but then we seem to run into a hardware issue: The 1.1V rail fails. It is supplied by a LDO of type TLV73311PDBVT which has internal 300mA current limiting. Could it be that the TUSB4041I actually draws that much current (datasheet says that only in SMBUS programming mode it would get to 225 mA)?

    In the meantime as a workaround for the overall project: How do we access OTP functionality? Is there a programming tool as well?

    Best regards,

    Sebastian.

  • In reply to Sebastian Wegner:

    Hi Sebastian,

    I am assuming that t you are seeing a overcurrent condition causing the LDO to reduce the power output correct? This may be caused by the inrush current at power-up. Do you only see the condition at power-on? You may need to use a LDO with constant current limiting or with a higher Imax.

    Also the OTP functionality is a programming tool as well and can be provided over direct message. 

  • In reply to Malik Barton57:

    Hey Malik, thanks for the swift reply.

    The condition as we see it now sure looks like overcurrent being detected by the 1.1V rail LDO (steep cut off of the output voltage). Also even in a situation where we are not trying to use the external EEPROM (pull up resitors on SDA and SCL) removed we see a very high total current consumption (3.3V plus 1.1V rail) of up to 400 mA that eventually drops when a connection is made to the upstream usb host. We are just now modifying the setup to measure the current per rail (removing the LDOs and supplying it externally) to assess the situation better, so we will know more tomorrow after further investigation.

    In the meantime to not keep the software team waiting any longer, we would like to try the potential workaround with OTP. Could you please share the respective programming tool as well?

    Best regards, Sebastian.

  • In reply to Sebastian Wegner:

    Hi Sebastian,

    I have already sent the software over e2e.

  • In reply to Malik Barton57:

    Perfect. Thank you. I will get back to you as soon as we have more insights - hopefully tomorrow.

  • In reply to Sebastian Wegner:

    Sounds good, I will wait on your reply.

  • In reply to Malik Barton57:

    Hey Malik, We have new results:

    After powering the TUSB4041I from an external lab supply we were able to use the EEPROM tool to input the desired config and it works. So far so good, but in the original configuration it will not work. The IC seems to have increased current draw on the 1.1V rail in certain conditions.

    • with no EEPROM attached and both pull-up resistors on the serial interface unassembled we get an acceptable current consumption of
      • 30 mA on 1.1 V and  10 mA on 3.3V with upstream USB connection established, no downstream connections
      • 50 mA on 1.1 V and  30 mA on 3.3V with upstream USB connection established and one downstream connection established (non USB-powered device)
    • with EEPROM attached and both pull-up resistors on the serial interface assembled however:
      • 320 mA on 1.1 V and 70 mA on 3.3V

    This is only if the EEPROM is NOT configured. After a successful configuration of the EEPROM and restart of the board we again get the acceptable values as it would be without EEPROM. Clearing the EEPROM completely (only setting first byte unequal 55h will not do the trick) and restart will give us the fault condition again.

    Next problem: Even with the EEPROM configured there will be a short time (few milliseconds) on startup when we get an increased current consumption on 1.1V (enough to trip the 300 mA overcurrent protection of the TLV73311PDBVT LDO that we have in the design right now. Again switching over to external lab supply we can work around this, but we still see the current being above 300 mA for a few milliseconds (does not look like inrush current). So bottom line: as soon as we have the I2C interface of the TUSB4041I configured with pull-ups in order to use an external EEPROM, the device definitely needs more than 300 mA on start up and will not work with a 300 mA current limited LDO.

    The datasheet states that the SMBUS programming current will be 225 mA on 1.1V. However we are well above that current and we don´t even have the device configured to SMBUS mode, but rather it is set for EEPROM mode. Also we don´t just see this problem while we put the device into the programming mode through switching the drivers and starting the EEPROM tool, but also at startup. I would not expect this behavior from reading the datasheet. Now I realize that the datasheet does not state "maximum" current, but it also does not seem to represent what is actually going on. Nonetheless it would probably be nice to update the info in there to actually make it understood that one needs.

    Also I sent you a private message about the OTP tool...

    Best regards,

    Sebastian.