• AD8138S: absolute maximum rating of  supply voltage

    I have a question to the absolute maximum ratings of AD8138S. When using the
    AD8138S with a +/-5V supply everything is clear from the data sheet. The
    absolute maximum rating is +-5.5V for the supply voltages. The point that in
    not fully…
  • Would mounting AD8138 on the top and bottom of a printed circuit board cause problems?

    The AD8138 layout recommends the two differential input pins (pin 2 and pin 9) to be kept a few millimeters from the ground plane, and ground should be removed from inner layers and he opposite side of the board under the input pins. However, my design…

  • AD8138

    Hi there,

    I am using AD8138 to make differential input for my ADC which does not have a S&H. The problem I have is the two differential signals are not balanced! Although the output of the AD8138 is balanced when I test it without having chip on my evaluation…

  • RE: Attenuate +-20V to +-2V for AD8138 Input

    Thanks ARoxas,

    I'm going to measure the transient voltage during capacitor charging and discharging.

    I want the +/-2V at the input of AD8138, but the voltage swing on capacitor is +/-20V.

    If I use the resistor voltage divider to attenuate the voltage…

  • RE: AD7934 full-differential mode

    Thanx for reply,

    Following way I've connected AD8138 (ADC driver) to AD7934.

    pin-4(AD8138) connected to pin-25 (AD7934)

    pin-5(AD8138) connected to pin-26 (AD7934)

    When I checked signal between VIN0-VIN1 of AD7934 it is coming as expected diff…

  • RE: AD9218

    Hello zhe-xin,

    Please note that the capacitor you reference in the AD8138 circuit is not across the differential input, but is actually between the Vocm input and ground.  A capacitor across the AD8138 differential input will cause problems, so this should…

  • RE: About ADC

    Hi Tom,

    Yes, I was able to review the AD8138 and AD9214 schematic blocks provided in your .png image files. I was unable to open the Altium Designer file provided in your .zip archive.

    By connecting the AD9214 REF output (1.25V) to the AD8138 VOCM pin…

  • AD8318 followed by AD8138

    I have an AD8318 Log Detector followed by an AD8138 Differential Driver.  The log detector is behaving correctly, as VOUT goes between 0.8-4.0VDC over the dynamic range of the input RF signal.  However, the AD8138 used to translate from single-ended to…

  • RE: AD9434 Analog Input Issues


    Yes, in Figure 41 the Output Common Mode Voltage (Vocm) of the AD8138 amplifier is established by the direct connection between the AD8138 Vocm input pin and the AD9434 CML output pin. It looks like the Vocm pin label was inadvertently left off the…