• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Subscribers 47 subscribers
  • Views 157 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.

LMH6518: Check a good replacement of AD8331

Yuxi Liu(Tony)
Intellectual 2380 points
Part Number: LMH6518
Other Parts Discussed in Thread: LMH6629

Tool/software:

Hi Tier

My customer is looking for an upgrade to the AD8331(adi) product, customer wants to increase chip performance which need have max gain to 70dB, other performance is basically the same as the AD8331, preferably INA.

Do we have a better device recommendation? 

Thank you very much.

  • 0
    TI__Mastermind 26015 points

    Hello Tony,

      Does the customer need the same bandwidth of AD8331 of 100MHz? Our INAs (instrumentational amplifier) have very high integrated gains that match what customer needs of 80dB. However instrumentational amplifier are fixed gains (not selectable gains) at lower bandwidths in the few MHz or below. 

    Thank you,
    Sima

  • 0 in reply to Sima Jalaleddine
    TI__Intellectual 2380 points

    Hi Sima

    Customer need large than 100Mhz, Could you give me some TI part number? I will let customer check Thank you very much.

    I made a mistake . Customer not need INA. It is nice to have a LNA (low noise amp) inside.

    Like AD8331: There is LNA inside.

    So if customer need max gain to 70dB VGA or PGA chip ,bandwidth large than 100Mhz, which chip do you recommend?

    Customers can also consider cascading the way to achieve a gain of 70dB, also please help to give some suggestions and solutions, thank you

  • +1 in reply to Yuxi Liu(Tony)
    TI__Mastermind 26015 points

    Hello Tony,

      Thank you for the additional information!  

      I was able to look through our portfolio of VGA/PGAs and our max dB is at 40dB for most of our devices. Unfortunately, we do not have a max 70dB VGA/PGA. However, we do have devices that have similar architecture that you showed with the LNA, but max gain is limited. Also, in our VGA portfolio, VGA/PGA > 100MHz with similar architecture as you have shown, would only be the one you linked from cross-reference which is the LMH6518 with a max gain of 38.8dB, 900MHz, and integrated LNA. 

      But, you said that customer would be able to cascade with two devices? Would either use a regular high bandwidth voltage feedback in first stage, or follow the VGA with a fully differential amplifier or another VGA/PGA? 

      Voltage feedback first stage suggestions would be: LMH6629, our high bandwidth ultra-low noise device that is available in a small package of SOT-23 (5) 2.90 mm × 1.60 mm. It can also be operated in a 5V supply.

    Thank you,
    Sima