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PGA280: Common-mode input range with VSOP = 3.3V

Part Number: PGA280
Other Parts Discussed in Thread: PGA281

Is the common mode input range of PGA280 affected if VSOP = 3.3V rather than 5V?  It appears difficult to answer from the datasheet alone, and of course there is no simulation model for this device.



  • HI Steve,

    The input common-mode of the PGA280 is limited by the input stage supplies (VSP and VSN).  Both inputs must remain within the range (VSN+2.5V) and (VSP-2.5V) or essentially 2.5V away from the VSN and VSP rail supplies as shown on the spec at the bottom of this post.

    The VSOP/VSON output stage voltage supply does not play a role on the input common-mode requirement, and will essentially only limit the output voltage range.

    There is no direct TINA model for the PGA280, however, the PGA281 is a similar device that uses the same amplifier core.   The difference between PGA280 and PGA281 is the PGA281 does not incorporate a multiplexer, the PGA281 is hardware pin controlled (does not use a SPI interface) and the high-speed current buffer available on PGA280 (current buffer useful to avoid in rush currents when changing mux channels) is not available on PGA281.

    Although the PGA281 does not incorporate all the features of PGA280, the PGA281 TINA macro model could be useful modeling the amplifier core of the PGA280.  

    PGA281 TINA-TI Reference Design

    Thank you and Regards,


  • Thanks, this looks pretty helpful.  -Steve

  • Hi Steve,

    Many Thanks,

    Let us know if you have additional questions.

    Thank you and Regards,