• ADA4857-2 and EVAL-ADA4857-2 evaluation board


    I recently bought the ADA4857-2 high speed opamp and the bare-board that allows me to prototype various circuits using the opamp. I want to create a circuit that converts the differential output coming from LTC5586 Zero IF IQ Demod board that I have…

  • RE: I am designing a circuit for driving a differential input ADC. As operational amplifier I use LTC 6254. My design works fine when simulating in LT Spice. However, when it comes to analyzing one of my outputs using a spectrum analyzer voltage level...


    You would at least need an amplifier with a THD of -72 dBc at fin= 5 MHz,  a much faster op amp would do so. Here are the possible choices: LTC6268/LTC6269, and ADA4857. Take note that ADA4857 runs at 5V and LTC6268/9 can run at 3.3 V. Also, reconsider…

  • How to use the Feedback (FB) and Power Down (PD) Pins of ADA4857 and ADA17

    I am trying to Configure an ADA4857-2 as an Instrumentation amplifier and I have simulated the circuit in ADS using the model and it is working fine. Now that I am making the schematics,I have encountered two pins which I do not know how to use and they…

  • ADA4857 pspice Model

    I am trying to use the ADA4857 to generate a circuit model of a state variable filter in order to compare with measured results.  In our implementation, we are using a single supply (+5V/0) on the ADA4857.  When using the pspice model of the ADA4857 in…

  • RE: ADA4857 SPICE Simulation Output Impedance

    Here is the pertinent connection info:

    From the model

    *Node Assignments
    * Non-Inverting Input
    * | Inverting Input
    * | | Positive supply
    * | | | Negative supply
    * | | | | Output
    * | | | | | FB
    * | | | | | | PD
    * | | | | | | |
    .Subckt ADA4857 100 101 102 103 104…

  • ADA4857 as charge amplifier

    We were using AD8620 Op Amp in our previous application but now want to use the ADA4857 op amp as integrator / charge amplifier. I have compared the following parameters of both the op amps

    Sl. No.
  • RE: ADA4857 Pspice Simulation


    The node or pin assignment is in the ADA4857.cir like this one below.

    Try to open the .cir file in the model editor or notepad.

  • RE: Photodiode design wizard: issues with op amp models

    Hi Ignacio,

    The SPICE models for the ADA4817, ADA4857, and AD8045 are attached. I will follow up with the ADA4899.

    I hope this helps.



  • Op Amp Active Filters

    What opamp do you recommend to use in Active filters Type C  (G=+1) for high BW loop filter (0.001 ~ 10MHz) applications?
    ADA4857,  AD8065, .. ? 

  • RE: Can I left the PD pin of ADA4857-1 unconnected for normal operation?

    I found these in ADA4861-3, which states that if PD function is not used, it is best to connect them to -VS (negative supply). I wonder whether this also applied to ADA4857-1.