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PGA308: About vout of pga308

DDdoor
Expert 2435 points
Part Number: PGA308
Other Parts Discussed in Thread: OPA320, OPA325

Hello,

Customer wants to extend Vout by 100mm to 300mm and connect to equipment. In that case, is a buffer amplifier required?

Best regards,
DDdoor

  • 0
    TI__Guru 55466 points

    Hi DDdoor,

    What is meant by the Customer wants to extend Vout by 100mm to 300mm and connect to equipment?

    What kind of circuit/equipment will the PGA308 drive? What are the impedance characteristics at the load at the PGA308 output, is the load capacitive or resistive?  

    If you have an schematic including the PGA308 supplies, and the circuit at the PGA308 output (or the PGA308 output load impedance characteristics0, we could look into making suggestions.

    Thank you and Regards,

    Luis

  • 0 in reply to Luis Chioye
    Expert 2435 points

    Hello,Luis
    There was no circuit diagram. The output of PGA308 seems to be input to the ADC of the microcomputer on the two boards.
    There is a figure of 1nF in the data sheet of pga308, so I think that it will be a guide,
    but this is the situation, do you have any other advice?

    Best regards,
    DDdoor

  • 0 in reply to DDdoor
    TI__Guru 55466 points

    Hi DDdoor,

    In order to answer your question, we need to have an schematic and understand which ADC device the Customer is using, the resolution requirements of the ADC and the maximum sampling rate or minimum acquisition time required in the application. 

    The PGA308 may be able to drive ADCs operating at slow sampling rates,  (around ~1-kSPS or so), where the allowed acquisition times are long.  However, the PGA308 will require a higher bandwidth amplifier buffer (such as the OPA320 or OPA325) in order to drive an ADC when supporting high sampling rates in order to drive the sample-and-hold of the ADC and settle within the allowed acquisition period.

    Thank you and Regards,

    Luis