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INA1650: Differential line receiver to drive upcoming TAA5212 ADC

Part Number: INA1650
Other Parts Discussed in Thread: TAA5212, , OPA1637

Tool/software:

For a pro audio application we've selected the upcoming TAA5212 as our ADC and are looking for a high CMRR input circuit to properly drive it. I'm relatively new in this field of EE, and am a bit lost what the best practices are here. Selecting for parts I've come across the INA1650, which has all the right specs but has a single ended (but referenced?) output. 

Could anyone point me in the right direction / share some example schematics on interfacing these types of TI differential line receivers with the differential TI ADCs? Would another solution be better? What are things to take into account designing such a circuit?

I'd love to hear,

David 

  • Hi David, 

    Our evaluation module/users guide may be a good place to start as we have it set up as a high common mode rejection line receiver. And there is flexibility to make the outputs differential. This is shown in the user's guide. 

    https://www.ti.com/tool/INA1650EVM

    User's Guide:

    https://www.ti.com/lit/ug/sbou178/sbou178.pdf?ts=1728590682782&ref_url=https%253A%252F%252Fwww.ti.com%252Ftool%252FINA1650EVM

    I have some Tina simulations I can share for explanation on some of the circuit possibilities with the INA1650. If you would like to run these simulations we offer Tina Ti for free in the link below. 

    https://www.ti.com/tool/TINA-TI

    Selecting for parts I've come across the INA1650, which has all the right specs but has a single ended (but referenced?) output. 

    Yes the output is referenced. For example say the ADC input common mode is 0V to 7V, we can set this to the center (3.5V). I have provided an example below. This is one example of how to achieve single supply operation. Although the INA1650 is differential in and single ended out, it is actually quite flexible and possible to get a differential out signal as well. The example below demonstrates one such possible configuration. 

    Note that the supply is a single 9V supply, the common mode voltage is set to mid supply or 4.5V and the outputs are set by the reference voltage of 3.5V. I am using a method in simulation to take a single ended signal and converting it to fully differential on the input. This is the SE to Diff Conversion block shown below. 

    6648.INA1650 Single Supply.TSC

    Here is another example of how to create differential outputs

    The big benefit with the INA1650 is the internal matched resistors that provide great CMRR performance. Other possible candidates include the OPA1637 which is a fully differential amplifier. 

    Let me know if you have any further questions. 

    Best Regards, 

    Chris Featherstone

  • Thanks you Chris, this is incredibly helpful! I'll dive right in and get back to you if anything's still unclear. 

  • Hey David, 

    No problem! Best of luck with your project. 

    Best Regards, 
    Chris Featherstone