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ADV7619KSVZ-P damaged at P126 (RXA_5V)

Dear Support,

We have a product using ADV7619KSVZ-P  HDMI receiver chip. Recently, we found this HDMI receiver chip was damaged on two units. By measuring the input resistances from Pin 126 (RXA_5V) to GND, it was found the resistance from this resistance is ~ 5 ohm on one unit and ~20 ohm on another unit. The measured resistances indicate that the input block of Pin 126 had been damaged. Here are my questions:

1. Inside the chip, is there a protection circuit for the Pin 126 (RXA_5V)?

2. If the is a protection circuit inside the chip for this pin, does the protection circuit could still protect this pin when the chip is not powered?

3. What is Absolute Voltage could be applied to Pin 126 when the chip is not powered?

4.  What is Absolute Voltage could be applied to Pin 126 when the chip is powered?

By the way, the HDMI input circuit design is same as Analog Device Evaluation Board. Please see the included Analog Device reference schematics.

Thanks.

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  • 1) The RXA_5V pin does have ESD protection.

    2) The ESD protection is a passive design such that even if the chip is not powered powered it is still possible for current flow.  I'd have to verify with the designers to be sure.

    3) I believe it is still 5.3V but I'd have to verify this with the designers

    4) 5.3V

    The RXA_5V pin is an input only.  The ESD protection is limited.  If your environment exceeds this level on energy hits than there could be problems.  Normally we have not seen problems with just connecting this pin to the outside world.  Since the pin is an input only you can put a 100 Ohm resistor in series with it.  This way the ESD energy would get absorbed in the resistor instead of damaging the silicon.  Also an ESD protection circuit in front 100 Ohm resistor would help even more.

    If I were to redesign this board for a higher ESD environment, I'd used something along this approach

    Also could use a series 22 Ohm in all the DDC and HP_ input lines as an alternative.

  • Hi GuenterL,

    Thank you for the quick response. The chip might be damaged when the units were tested with a hand-hold HDMI tester. The HDMI tester is a HDMI pattern generator. the HDMI tester was connected to the units when the unit was not powered. I wondered if the up-powered unit is a factor for the damage. So please confirm if the ESD protection still works when the chip is not powered.

    Data sheet shows the Absolute voltage for 5v tolerance pins is 5.3V. However, the RXA_5V did not listed as 5V tolerance pin below that table. Please confirm the 5.3V for this pin.

    Thanks.

  • RXA_5V is a 5V tolerant pin.  ESD confirmation will take some time

  • Thanks. Please let me know when you have the confirmation. We are trying to figure out on which of the testing step the chip was damaged.

  • Here are the ADV7619 ESD test results:

    This test was applied to all pins