• Simulation Problem of ADA4938-1

    Dear Emman.A,

             I want to use ada4938-1 to drive the ADC ad9629, before we start the design,  I do the simulation of ada4938-1, but I met some problems when I do the simulation. 

    software: Orcad PSpice

    the steps of simulation:

        First , I get…

  • Correct operation of ADA4938-1...

    I would like to ask if it is possible to use Cf - capacitors parallel to Rf - resistors in feedback like with AD8138 (Figure 42. Circuit Definitions in datasheet) with this differential amplifier (ADA4938-1)? Will be it stable? I want to use it like…

  • exact value of the differential output impedance of the ADA4938-1 or ADA4938-2

    Q 

    What is the exact value of the differential output impedance of the ADA4938-1
    or ADA4938-2. Is it 2ohm or 5ohm or 20ohm?There are S parameter plots S11 nad
    S22 in the datasheet but I don't know to which circuit they apply to or to
    …

  • ADA4938 not static CMRR at low frequencies

    We are reevaluating the use of the ADA4938. The CMRR is specified to be TYP: -75dB @ ∆VIN, cm = ±1 V, f = 1 MHz.

    The CMRR measured on an Eval Board with ADA4938 reveals, that the CMRR is strongly frequency dependent. (red curve: ADA4938, blue: ADA4932…

  • What is the impedance of ADA4938-1 in Power-Down mode

    I intend to multiplex the outputs of two ADA4938-1 devices into an ADC type LTC2387-18; I want to confirm this is possible using the Power-Down feature or I have to include a dedicated multiplexer.

    Thank you.

  • ADA4938-1的供电问题

    最近在用ada4938-1芯片实现单端口转差分端口的功能。ada-4938需要正负5V供电，但是不知道供电电流需要多少。

  • RE: ADA4932/38 recommended RG and RF

    Hi JinoL,

    Thanks for your comments. I have one more query on ADA4938. 

    I have configured the ADA4938 in Differential to single-ended and single-ended to differential configuration and observed the noise floor. I have used the ADA938 evaluation board from…

  • Does the voltage of pin Vocm influence the gain of ADA4938?

    Hi ,

       I use the ADA4938 to Drive the ADC(AD9629), the pin Vocm connected to pin VCM of AD9629, and the output voltage of pin VCM is MID AVDD Supply (0.9V).

    The schematic is shown below, and the gain of ADA4938 should be 0.5 in theory. 

       When the…

  • RE: how to reconcile the capacitive sensor with a close differential amplifier?

    • Hi Jino,
    • there is capacitive sensor that gives a signal in the frequency band 0-500mHz. I want to be placed in it close proximity amplifier (ada4927 or ada4817or ada4938 or ada 4939) amplifier with a gain of 1-2 and hand it to an oscilloscope. How…

  • ADA4938-1:  Can I leave PD pin unconnected?

    Q 

    If the powerdown feature is not to be used, can the PD pin be left unconnected?

     

    A 

    Yes it can.