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Use of ADV7125 as a general DAC

Use of ADV7125

1. Can the three RGB (six differential) outputs of controlled independently if sync_n = 0 and blank_n = 1? I this case, are the RGB outputs true differential?

2. Can this device drive single terminated 50 ohm loads?

3. Is it truly 330 MSPS?

4. What is the op-amp to convert the differential current outputs to single-ended voltage outputs?

5. Does the clock input need 50 ohm impedance matching?

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  • See answers below:

    1. Can the three RGB (six differential) outputs of controlled independently if sync_n = 0 and blank_n = 1? I this case, are the RGB outputs true differential?

    >>>> The outputs are complementary outputs. Refer to the table attached here.

     

     2. Can this device drive single terminated 50 ohm loads?

    >>>> if the analog output current is within that specified in the data sheet, I see no reason the ADV7125 cannot drive a 50 Ohm load

    3. Is it truly 330 MSPS?

    >>>> The 3.3V version of the ADV7125JSTZ330

    4. What is the op-amp to convert the differential current outputs to single-ended voltage outputs?

    >>>> As previously mentioned above the analog output currents are complementary, so use either IOG/IOR/IOB current output. Rset resistor in your design will set the value of the output current. This current develops a voltage on your load. So the equation for output current = (7989.9 * VRef/RSET). Mind you the voltage developed should not be more than the output compliance (Voc) of the DAC. Typically other customers have used the AD827.

    5. Does the clock input need 50 ohm impedance matching?

    >>>> You need to choose the damping series resistors on the clock line to match your overall PCB board impedance.

Reply
  • See answers below:

    1. Can the three RGB (six differential) outputs of controlled independently if sync_n = 0 and blank_n = 1? I this case, are the RGB outputs true differential?

    >>>> The outputs are complementary outputs. Refer to the table attached here.

     

     2. Can this device drive single terminated 50 ohm loads?

    >>>> if the analog output current is within that specified in the data sheet, I see no reason the ADV7125 cannot drive a 50 Ohm load

    3. Is it truly 330 MSPS?

    >>>> The 3.3V version of the ADV7125JSTZ330

    4. What is the op-amp to convert the differential current outputs to single-ended voltage outputs?

    >>>> As previously mentioned above the analog output currents are complementary, so use either IOG/IOR/IOB current output. Rset resistor in your design will set the value of the output current. This current develops a voltage on your load. So the equation for output current = (7989.9 * VRef/RSET). Mind you the voltage developed should not be more than the output compliance (Voc) of the DAC. Typically other customers have used the AD827.

    5. Does the clock input need 50 ohm impedance matching?

    >>>> You need to choose the damping series resistors on the clock line to match your overall PCB board impedance.

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