• State
  • Locked Locked
  • Replies 2 replies
  • Subscribers 50 subscribers
  • Views 582 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.

Looking for 1W 40dBm amplifier to pair with LMX2571 driving 10 ohm load, a fairly capacitive load

James Friend
Prodigy 10 points
Other Parts Discussed in Thread: LMX2571, THS6182

Hello,

Am intending to use the LMX2571, and seeking to use it to drive 1W to an 10 ohm impedance load at a fixed frequency of (depending on design): 4 MHz, 30 MHz, 100 MHz, 250 MHz from a battery. Wondering if there might be a suitable choice for this purpose?

Thanks,
James

  • 0
    TI__Genius 15975 points

    Hello James,

    I don't think we have a single 1W or 40dBm amplifier driving 10ohm load for your frequencies of interest. A power level of 40dBm into a 10ohm load corresponds to ~28Vpp which means into a 10ohm load would mean +/-1.4A. The closest we have for output current drive capability is the THS6182 with +/-600mA into a 10ohm load for 4MHz and 30MHz frequencies. It might also be possible to parallel two op-amps to achieve the swing needed, something that you can try following this blog:

    You can also try to take a look at other possible parts:

    Best Regards,

    Rohit

  • 0 in reply to Rohit Bhat
    Prodigy 230 points
    1W or 40dbm (10W), it makes a difference (or do you mean 1W, 40db gain)?

    Is that power rating at 1dB compression or at saturation?
    Also, can you tune the load to give a resistive match at the operating frequency?
    Some sort of L match or similar is fairly standard RF design and apart from anything else if you match the load to 50 ohms then all the standard RF test gear becomes far more usable as it is almost all designed on the assumption of a 50 ohm port.

    A THS6182 or similar pushing a push pull pair of modest RF power transistors coupled by a few 43 mix ferrite transformers would be my take on this problem, not everything has to come as a packaged chip.

    Regards, Dan.