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THS3201: ths3201

Part Number: THS3201
Other Parts Discussed in Thread: THS3491, , LMH6703

Dear TI team,
I intended to use TH3201 in my design, but just recently I noticed that you do not recommend using it for new designs and it is recommended to use THS3491 instead which is not proper for my application due to its lower bandwidth (900MHz BW compared with the previous 1.8GHz Bandwidth). 
Moreover, low system delay is crucial in my design, which despite to higher slew rate, has more rise and fall time of THS3491 (1.3ns compared to 0.7/0.9ns) that imposes another problem for me.
In this regard, I would appreciate it if you could introduce me another alternative for THS3201 with a bandwidth of more than 1.5 GHz and a rise and fall time of less than 0.7ns. 

  • The current-feedback amplifier with the highest bandwidth is the LMH6703; its slew rate is lower than that of the THS3201.

    Here is a list of other fast amplifiers: ti.com/amplifier-circuit/op-amps/high-speed/products.html#23typ=1800;8000.

  • Thanks for your answer, but LMH6703 has still 400Mhz less bandwidth than TH3201, in addition to having lower slew rate which is not desirable for my project at all.
    In case there is not any proper alternatives, can I still order THS3201 for my project?
    And may I know whats the problem with THS3201 that you do not recommend it anymore?

  • Hi Mahsa,

    Can you share more information about your application for which you are looking for a part? From my understanding you are concerned about the bandwidth, slew rate, and rise/fall times.

    When you are looking at the bandwidth of the THS3201, the 1.8GHz of bandwidth is measured for a noninverting small signal input in G=1 as shown in the figure below:

    However, slew rate and rise/fall times tend to be specs that are important when outputting large signal responses. So let's compare bandwidth of THS3201 (left) and THS3491 (right) frequency response for an output voltage of 2Vpp in G=5 below

    You can see that the THS3201 has a -3dB large signal bandwidth of approximately 600MHz and the THS3491 has approximately 900MHz -3dB bandwidth for Vo=2Vpp. Also, the THS3491 has a high 6000V/us slew rate in a G=5, Vs=+/-7.5V, Vo=10Vpp configuration which is close to that of the THS3021 in a G=2, Vs=+/-7.5V, Vo=10Vpp configuration.

    I point out these details to highlight that the application is important to understanding what specs are necessary when considering a part. I believe the THS3491 is a good alternative to the THS3201, but if you are able to share more information about your application and input/output signal requirements, I can help find a suitable part.

    Thanks,

    Nick