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OPA355: Non inverting input 50ohm termination on data sheet layout example

Part Number: OPA355


Now I am considering non inverting amplifier circuit (gain 2) using OPA355.
Layout example is shown in figure 40 on OPA355 data sheet.
"Noninverting input terminated in 50ohm" is recommended on figure 40.

I would like to confirm the meaning of this recommendation of 50ohm termination.

I am wondering if it is necessary to add a 50ohm terminating resistor to the + input of the non-inverting amplifier circuit.
Further, Place another opamp circuit at the signal source in the immediate vicinity of this non-inverting amplifier.


  • Morning Mesh

    That 50ohm termination is principally for characterization coming from 50ohm signal generators through 50ohm cables - you need to adapt your design to the specific requirements. Matched termination gives the best signal fidelity if you have to move the signal longer distances, if not, you normally don't need it - all depends on where your signal is coming from? 

  • Good morning, Michael

    Thank you for your reply.

    I thought that if there were any special conditions on OPA355, I would need to be careful, so I confirmed it.

    Your reply is very helpful for me.