AD8390 or AD8390A For Differntial Audio Output Stage

The AD8390 seems an excellent candidate for use in a differential drive stage for an audio-frequency drive to a resolver in a motion-control situation.  Is there any particular concern or reason why this would not work, or why this is a poor choice?  We need roughly the full drive capacity of the chip in some applications, though the actual drive requirements will vary a lot from application to application.  Some will be highly inductive, some nearly purely resistive, and some may be slightly capacitive.

These parts also look like they would make killer headphone amplifier final-drive stages, anyone try this yet?

Is there a SPICE model available for the AD8390 or AD8390A?

  • Hi,

    Thank you for your interest in AD8390/AD8390A. The part is intended for higher speed applications such as ADSL/ADSL2+ CO and CPE line drivers. Most of the Typical Performance Curves only shows data from 1MHz and above. I will talk to the Apps Engineer of AD8390 regarding your concerns including the availability of the SPICE models. For the mean time, may I ask what particular specs for your audio driver that you are interested most? ADI has also a wide range of Precision Amplifiers (BW<50MHz) that could better fit your requirements.

    Best regards,

    Neil

  • Neil,

         Thanks for the reply.  What I find especially inviting about the AD8390 is that I can get the current drive I need for my application in a single 4x4mm package.  Other options require either external BJTs/FETs to boost the current or else multiple SO-8 type packages.  I basically want to be able to drive up to 40V pk-pk (+/-10V differential) into anything from a slightly capacitive 50 Ohms to a highly inductive 50 Ohms to a highly inductive several hundreds of ohms.  In other words, I need a fairly broad drive capacity into a fairly wide-range of loads.  The 8390 appears to be an excellent fit drive-wise and I have modeled my circuit using another manufacturers xDSL amplifier with excellent results.  I am interested in the ADI part for a few reasons - smaller package, more thoroough data sheet, especially with regards to thermal issues, better price point (though that one is not so important for us).  Nothing else in the ADI op-amp line even comes close to this part with regards to drive capacity, physical footprint, and price.

    Regards,

    Steve

  • Hi Steve,

    I already received the feedback from the Applications Engineer of AD8390/AD8390A. He said that although the part was design for ADSL applications, he doesn't anticipate any issues with your application. He recommends though that you carefully look into power dissipation since you require the full drive capacity of the device. Also, I regret to inform you that there isn't a SPICE model available for AD8390.AD8390A.

    Best regards,

    Neil

  • 0
    •  Analog Employees 
    on Aug 2, 2018 2:24 PM over 2 years ago
    This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

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    EZ Admin