analog & digital repeater/buffer

Discussion in 'The Projects Forum' started by JoeLebowski, Nov 22, 2013.

  1. JoeLebowski

    Thread Starter New Member

    Nov 22, 2013
    Hello all,

    I am currently working on a motor controller project. I don not have a lot of experience in this, so I would like to get some feedback from people with experience in this field. I would like to make two repeaters/buffers on my board. There are 2 kinds of incoming signals at the input of my board: Differential digital and sine waves. These signals are going straight to a controller, but I also want to repeat them, so I can output these signals to an external device.
    There are 3 differential block signals, with a voltage difference of about 3.4 V at frequencies ranging between a few Hz to max 20 MHz. The amplitude of the digital repeated signal is not critical. The frequency of the block wave is.
    The other one should precisely repeat 6 sine waves (amplitude about 0.5V, offset 2.5V) at frequencies ranging from a few Hz to maximum 20MHz. For this analog signal, the amplitude is critical. In both cases i would like to connect a 2 to 3 meter long STP or FTP-cable from the repeater to the external device. For the analog signals, I am thinking about going for the OPA4820. It has 4 channels and seems to have a high enough bandwidth, without too much noise.
    Is this in your opinion a good choice for the analog signal? Could I use this same opamp for the digital signal or should I look for a dedicated differential buffer IC's with a differential output?
    To clarify, I have added a small drawing.
    I would really be really thankful if someone could help me with this.