question about ADG787 spice model showing excessive leakage current

In the ADG787 spice model, switch SWITCH.SMOD1 is modeled with a Roff of only 2.5 Mohm, whereas all the other switches are modeled with at least 10^11 ohm off resistance. This is resulting in an unacceptable leakage current of several uA in my application in the simulation whereas the datasheet specifies leakage currents a few nA only. Is this is an error in the spice model? If it is not an error, how can this behavior be compatible with the datasheet specifications?

  • Hi tomtorf,

    Let me check on this. I'll get back to you soon.

    Regards,

    May

  • Hi tomtorfs,

    As I have observed in the ADG787 spice model, the switch SMOD1 uses an Roff of 2.5Mohm is to comply with the On Resistance parameter of the datasheet and also to avoid convergence error in PSpice. It is adviced that the Ron from Roff range must not be greater than 1e9. However, you may configure the Roff of SMOD1 to as high as 10^11 ohms and start from there. If this causes error then I'm afraid we have to settle for the existing Roff value.

    Hope this helps. Let me know if you need anything else.

    Best Regards,

    May