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TLC6C5712-Q1: Fault situation during thermal test

Chase Jeong
Mastermind 7645 points
Part Number: TLC6C5712-Q1

Tool/software:

Dear TI experts,

My customer tests their product in high temperature. During the test the device failed.

And my customer sent me some questions about the results. Could you check these questions?

1. Test with the condition of 95℃ ambient temperature.

2. In the test, Tj is measured over 150℃ a little.

3. After about 3 days with over Tj=150℃, Fault situation from \ERR pin occured.

Even ambient temperature went down to 25℃(room temperature), \ERR pin is low.

In the schematic below, LEDs which are connected to B/L_x is worked well, but LEDs which are connected to H/L_x is not controlled well.

Here are my questions;

1. In the datasheet, maximum junction operating temperature is 150℃. Do you have any margins about this value?

(i.e. it is okay to reaching a junction temperature up to 165℃ because there is 10% margin.)

2. What is minimum time which the device get damaged with Tj=150℃?

(i.e. The device would be damaged after 10 minutes with Tj=150℃.)

3. What is expected failure situation if the device is damaged due to over temperature?

Please check this issue. Thanks.

Best regards,

Chase

  • 0
    TI__Intellectual 920 points

    Hello Chase,

    Yes, the device absolute maximum rating for junction temperature is 150C. Since the test ambient temperature caused the junction temp to exceed 150C, the typical performance cannot be guaranteed. I will check to see if we have FIT documentation on overtemperature failure for this part but I do not believe so.  

    There is a pre-thermal warning for junction temperature between 125-150C to allow an MCU to respond to the warning. If temp continues to increase, there is a thermal shutdown from 150-165C. Both pre-TSD and TSD will cause ERR pin to be pulled low with Flag registers latched. These flags can be reset with RESET_STATUS command. 

    I don't see an attached schematic so I cannot review B/L_x and H/L_x.

    Best,
    Isaiah 

  • 0 in reply to Isaiah Atsedewoin
    Mastermind 7645 points

    Dear Isaiah,

    Thank you for your support.

    Could you check the schematic related to B/L_x and H/L_x pins?

    Best regards,

    Chase

  • 0 in reply to Chase Jeong
    TI__Intellectual 920 points

    Hello Chase,

    I don't see anything that would cause BL_x to have control and not HL_x besides utilizing different LEDs. This could just be the nature of how the device was damaged. 

    We do have a FIT rate document that you can find by searching the part here: https://www.ti.com/quality/docs/estimator.tsp 

    Regards,
    Isaiah