Hello,

I have a question about output of ADV7392.

Please refer attached file "ADV7392_2Voutput".

Thank you.

Best regards.

Hello,

I have a question about output of ADV7392.

Please refer attached file "ADV7392_2Voutput".

Thank you.

Best regards.

- 1 person found this helpful
The ADV7392 was designed and tested for 75 and 300 Ohm outputs only. However the device is a current output DAC with Rset controlling the current. The customer can tweak this value and re-test to his requirements. (Try Rset ~2k) . The real issue is can the device output DAC drive current into a load up to 2V with the required bandwidth. I do not think so.

ADI can not guarantee operation if the circuit is not implemented as shown in the data sheet.

Question #1:

In the data sheet there is a note "The recommended mode of operation is for the DACs is Full Drive (Rset = 510 Ohm, Rl = 37,5 Ohm). So what you have drawn will be an effective load of 37.5 Ohm, the output would be 1Vpp. I am not sure why you need two 150 Ohm resistors. Just make the first one 75 Ohm and remove the second 150 Ohm completely then the circuit would be exactly what is in the data sheet. The buffer amp is just there so we can have the 75 Ohm series resistor for better control down cable.

Questioin #2

I am not sure what bias you are talking of. The outputs are just DACs which for input code = 0 gives 0 current and input code = full gives full output current.

Question #1:

In the data sheet there is a note "The recommended mode of operation is for the DACs is Full Drive (Rset = 510 Ohm, Rl = 37,5 Ohm). So what you have drawn will be an effective load of 37.5 Ohm, the output would be 1Vpp. I am not sure why you need two 150 Ohm resistors. Just make the first one 75 Ohm and remove the second 150 Ohm completely then the circuit would be exactly what is in the data sheet. The buffer amp is just there so we can have the 75 Ohm series resistor for better control down cable.

Questioin #2

I am not sure what bias you are talking of. The outputs are just DACs which for input code = 0 gives 0 current and input code = full gives full output current.