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BUF634: BUF634

Part Number: BUF634
Other Parts Discussed in Thread: LME49600,

Hello,

I am looking for a buffer (Analog) with the following requirements:

1) Input voltage range: 0V to 0.9V

2) Fq: ~100MHz to 200MHz

3) Iq, Noise: We don't really care about it

4) VDD: We can provide any VDD between 0.9V to 3.3V (Or may be even higher if needed)

5) Should have very (very) low input capacitance. Kind of main requirement for this buffer. (May be less than 1pF?? I know its difficult to get it) If input doesn't have ESD protection, it will work for us.

I searched TIs website and found out two close ICs: BUF634 and LME49600. Are these the two options available for our specs or do you suggest something else?

Thanks!

  • Forgot to mention: Input is single ended and is not differential...
  • Hello Premsagar,

    The BUF634 and LME49600 are gain less than 1 V/V buffer amplifiers. They are intended to follow an operational amplifier and be placed within the feedback loop. Therefore, they may not be the best choices for your application. Also, I suspect that for a 0 to 0.9 V input signal having a frequency of 100 to 200 MHz, that a higher bandwidth amplifier is going to be required for accurate reproduction of the input signal. Our Precision Amplifiers op amps are rated with bandwidths up to 50 MHz so what you likely need is a high-speed op amp with much higher gain-bandwidth than that.

    TI's High-Speed amplifiers group should be able to review your requirements and provide recommendations from their product line. It is possible that a high-speed op amp configured as a buffer amplifier (G = +1 V/V) will be the best bet. Many of the high-speed op amps have high output current capabilities. I do think the 1 pF input capacitance could be an issue for them, but I may not be correct on that point.

    The High-Speed Amplifier group has their own E2E forum found here:

    If you can close out this particular E2E thread that would be helpful to us.

    Regards, Thomas

    Precision Amplifiers Applications Engineering

  • Sure. Thank you for your suggestions..
  • Hi Premsagar,

    datasheet of BUF634 mentions an input capacitance of 8pF.

    Kai
  • Ya, I saw that. But I could not find anything significantly lower compared to BUF634. I have asked the same question in High-Speed Amplifier forum. Awaiting for their reply. Thank you!