• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 2 answers
  • Subscribers 51 subscribers
  • Views 986 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.

OPA4348: what should be considered when choose single stage or multistage amplifier?

Yuan Tan63
Expert 3280 points
Part Number: OPA4348

Hi,

Do you have material about performance comparison or design consideration when choose single stage or multistage amplifier? like bandwidth, noise..

thanks!

Yuan

  • 0
    Guru 140200 points

    Hi Yuan,

    what do you mean by multistage? In series or in parallel?

    You can massively increase the overall bandwidth when replacing a single stage amplifier by a two- or even multistage amplifier mounted in series. But you will see no an advantage in noise performance because only the first stage mainly determines the overall noise.

    A paralleled multistage amplifier, on the other hand, can considerably decrease the noise:

    Can you show a schematic of your application or give further details?

    Kai

  • 0
    TI__Genius 15410 points

    Hi Yuan,

    As Kai mentioned using multiple gain stages will increase the overall usable bandwidth of the circuit.

    To optimize the circuit it is recommended to put as much gain in the first stage as possible. This will minimize the amount the error sources in the second stage are amplified by minimizing the total noise and offset error of your system.

    Thank you,

    Tim Claycomb

  • 0
    TI__Expert 7285 points

    Hi Yuan,

    The number of amplifier stages is determined by the gain and bandwidth requirements of the circuit. For high-gain applications, multiple stages can be cascaded in series to effectively “spread” the gain out between stages. This makes use of the gain bandwidth of multiple op amps to increase the bandwidth of the system.

    Of course, additional gain stages mean additional noise sources to consider. Typically a majority of the gain is applied in the first stage of a multi-stage amplifier. This ensures that the noise of the first stage dominates the noise of the amplifier, and the contributions from later stages are negligible. This same principle applies for offset voltage.

    The OP4348 is a quad-package, meaning you can design up to four amplifier stages with a single IC. This allows for a lot of gain staging options, each with trade-offs in bandwidth, noise, and offset.

    Zach Olson