Because of the Thanksgiving holiday in the U.S., TI E2E™ design support forum responses may be delayed from November 25 through December 2. Thank you for your patience.

  • State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 47 subscribers
  • Views 384 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

ths3091 vs. ths3061

mark kovach
Intellectual 300 points
Other Parts Discussed in Thread: THS3091, THS3061

As shown on pg.18. of the ths3091 white paper (for non inverting wideband operation) and using table 1. for Rg and Rf values for a gain of 5;

Would the same hold true for the ths3061 as a drop in?  If not, please give a reasonable explanation.

I see that for unity gain the 3091 recommends 1.78K while the 3061 recommends 750R but I'm looking at gain of 5X input of up to 2V, supply 0f +/-12Vdc,  and Bandwidth is not as important (it's in an audio design so 200K is fine) as total stability and accuracy. 

So, generally speaking are they comprable?

Thanks!

  • 0
    TI__Expert 4625 points

    Hi Mark,

    The recommended resistor values to achieve a specific gain setting with the THS3091 will not be the same for the THS3061.  The reason for this is that both amps are current-feedback amplifiers.  With current feedback amps, the bandwidth is inversely proportional to the value of the feedback resistor.  Because of this, different current feedback amps have different optimum values for feedback resistors in order to get the best possible frequency response.  The recommended values of resistors for the THS3061 and THS3091 should be kept separate in order to achieve the best freq. response for each respective part.

    An application note that goes over the details of current feedback amp analysis is available here: http://www.ti.com/litv/pdf/sloa021a

    Both the THS3091 and 3061 are capable of handling a 10V output swing if powered with +/-12V supplies and they both have sufficient bandwidth.  However, these current feedback amps are typically used for higher speed designs and aren't focused on the audio frequencies.   What is your specific application?  If you provided more requirements, I think there might be a better amp for your application.

    Please let me know if I can help out with any other questions.

     

    Regards,

    Nick - TI High Speed Amps