ADV7280A Reset Pin

Hi,

  Please try the below sequence regarding RESET,  As per recommended script, the normal sequence would be follow as like below i2c configuration,

PoornimaSubramani said:

belo

I am following exactly this sequence, but it does not work.

My test setup is as follows:

I turn on the power supply for my board.
This powers the ADV7280A with 3.3V and 1.8V.
At this point, the PowerDown and Reset lines are still at 0V.

Next, I set the PowerDown line to 3.3V.
Wait for 200ms,
Then set the Reset line to 3.3V.
Wait for 10ms.
Then I send: 42 0F 80 -> Of course, I don’t get an ACK back.
Wait for 10ms.
Send 42 0F 80 again -> This time, I get an ACK back.

Now, I can fully configure the ADV7280A via I2C, and it works as expected.

However, when I no longer need the video functionality, I want to put it into PowerDown mode.

I cannot switch off the 3.3V and 1.8V power supply, as it remains on continuously!

I set the PowerDown line of the ADV7280A to 0V, and then immediately set the Reset line to 0V as well.

If the video signal is needed again, I want to reactivate the ADV7280A:

I set the PowerDown line to 3.3V.
Wait for 10ms.
Then set the Reset line to 3.3V.
Wait for 10ms.
I attempt to send 42 0F 80 via I2C, but the ADV7280A does not send an ACK for the byte with the address.

All subsequent I2C attempts also fail, with no response from the ADV7280A. It seems to remain stuck in reset.

I have checked the PowerDown and Reset lines with an oscilloscope, and they are being toggled as described.
However, the ADV7280A remains unresponsive.

It only starts working again if I completely disconnect and reconnect the power supply to the entire board. After that, the initialization works as expected.

Is there an explanation for this? Is it mandatory to turn off the 3.3V and 1.8V power supply when using the hardware Reset line?

If I put the chip into PowerDown mode via I2C and then wake it up again via I2C, it works. However, I would prefer to use the hardware lines.

Hi,

   At first, Please crosscheck your schematic with our reference one, How we are making the RESET and Power domain at (+) ADV7281/ADV7281-M / ADV7281-MA Design Support Files - Documents - Video - EngineerZone

  Also Kindly refer Power Supply Sequencing at Page16 ADV7281 (Rev. B) and follow the sequence as per our specification.

Thanks,

Poornima

I'm talking about the 7280A and not the 7281A!

And yes, I compared the schematic with the reference schematic and have the same setup.

And I wrote that I stick to the power sequencing. But as soon as a reset is triggered via the GPIO pin, I2C communication no longer works.

I wrote everything step by step in the previous post and I have the feeling that the post wasn't read completely.

That's a real shame

Hi,

I'm talking about the 7280A and not the 7281A!

      Note that, Both are same family only.

  We don't know, how u have making the connections in your custom board So we can't give exact solution to your problem.

 Your issue relate to the hardware point of view and this we need to check with part specialist but it will take time for their response.

  If you want to expedite the process, then evaluate in our 'ADV7280A evaluation board'.

Thanks,

Poornima