ADC (video decoder) --- ADV7181B

[alaurella]

Dear Sirs,

I have implemented your ADV7181BBSTZ Video decoder from Analog Devices. I found two recommendations of xtal value in the circuit implementation,first with a 27MHz xtal and another one with a 28.6363MHz Xtal.

I chose the one with 27MHz xtal, but when I switched on the IC, I got 9 MHz instead of 27 MHz.

I would appreciate it if you could tell me what could be wrong with this circuit.

Thanks in advance.

 

[cydi]

upload the circuit please, there seems to be a connection error

 

[l_alexey]

1. You must use 27MHz FUNDAMENTAL quarz (1-st obertone), maybe you use 27MHz 3-th obertone quarz?
2. Probe capacity can be too high for normal oscillation. Your must connect 1:10 probe with lower capacity.

We are planing to use this decoder. Which layout are you useing (4 or 2 layers)

 

[mondunno]

learn signal integrity topics on google. some sort of bandwidth problem? dunno. but 27MHz shouldn have such problems with that. change the crystal with a new 27MHz, i can only help with these details.

upload the layout if u could