ADG2128 - supply down to 5V possible?

We do currently have a development which utilizes the switch array ADG2128. Unfortunatley there is no information about the minimum VDD supply with VSS=GND.

 

If I take a look at Fig 4 it seems that only the difference between supply and source voltage is of importance (only NMOS-switches?)

 

High on-resistances are not that crictical because the signal is forwared to an Differential OpAmp stage with >10Meg input impedance.

 

For my work it is only of interest if the switching matrix works at 5V and does not have any shortcut-like or other undefined behaviour. So let's assume the following: I have VSS=0, VDD=5V and source-voltage is 1.5V. Then the on-resistance should be about 60 Ohms, right?

  • 0
    •  Analog Employees 
    on Sep 26, 2016 7:03 PM

    Hi Wissenwisserj,

    You may use the ADG2128 with Vdd=5V and Vss=0V. However, VL should still be at 5V. Please be reminded that VL sets the logic power supply of the part so it is necessary to retain it at 5V to ensure that the part would still perform as expected.

     

    There will be changes in the parametric values of the device due to the changes in Vdd supplies. Please be reminded that we only guarantee specs tested and stated in the datasheet. So for on resistance, it would be possible to have 60 ohms or greater. Also, analog inputs would be limited since the part will be operating at +5V single supply only.

     

    Best Regards,

    May

  • Thank's for the information.

    However, one question is still open: You state (as well as the bigger part of the datasheet) VL=5V. However, there is also Fig.23 which seems to allow VL=3V (which makes more sense for my application).

  • 0
    •  Analog Employees 
    on Sep 29, 2016 12:17 AM

    Hi Wissenwisserj,

    Yes, VL=3V is also used at Fig.23. However, besides the graph on Fig.23, with VL=3V, other parameters like VINH, VINL and IIN are not guaranteed. If you'll have a look at the Specifications Table of the datasheet, this part is only tested at VL=5V. Please be reminded that we can only guarantee the performance of the part that operates within the specifications table requirements.

    Let me know if this helps.

    Best Regards,

    May