AnsweredAssumed Answered

ADV7611 problem

Question asked by KaiBTec on Oct 21, 2012
Latest reply on Nov 7, 2012 by GuenterL

Hello!

 

We made a custom board with the ADV7611. We have an ADV7611 evaluation board to cross check.

 

The problem:

I'm able to communicate with the ADV7611 via I2c (Pin 53/54, transfers are acknowledged as expected) and can initiate it. I use the i2c transfers described in this topic: http://ez.analog.com/thread/9106

 

After theese i2c transfers the i2c slave on the DDCA_SCL/SDA lines does not acknowledge to any slave adress (e.g. 0xA0) which I would expect.

 

I checked:

  • Supply voltages directly at the pins => Same as on the evboard.
  • HPA-input is high when HDMI is connected, as on the evboard, RXA_5V also (Directly connected to HDMI +5V output)
  • Reset input => behaves as expected (low for a short period after power up, afterwards HIGH)
  • I2c pullups to  +5V on DDCA_SCL/SDA lines are present
  • All connections are ok
  • The crystal does not oscillate. This is the only difference I can see when comparing with the evboard. I desoldered the crystal and capacitor from the evboard and soldered it to our board without success. The crystal-circuit is identical to the evboard one. The 390k resistor is also present and the value correct.

 

Does anybody have an idea what the root cause for this problem can be?

 

Best regards and thanks for your support,

 

Kai

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