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MSP430G2353 external interrupt voltage levels ...

We're designing a system to wake up from sleep on an external interrupt.  By design, the pin has a pull down resistor and filtering cap, and when power is plugged in the pin voltage rises to 2.5V (VCC = 3.3V).  However there is a leakage path from our battery to this pin that is impossible to remove.  Because of this the pin voltage floats to around 1.2-1.4V.  We could decrease the value of the pull down resistor to compensate for the leakage into the node, but the lower the value the more battery charge we lose.  Because of this we're trying to avoid this solution.  

On the particular chip I'm designing with, the transition from this floating voltage to 2.5V is enough to wake it up.  However I don't feel confident that this will work on every unit when we get into manufacturing 3k+ per year.  I've read through the electrical characteristics in the data sheet, but I'm having a hard time parsing it.

Can someone clarify for me?  I'm looking for the minimum voltage delta needed to detect a rising edge on 100% of the MCU's we populate in this product.  

  • Use a msp430 with build-in lowpower comparator
    Use an external comparator like TI's TLV3691IDCKR

    Use a uplevel translator like TI's SN74LV1T34DBVR
    though you have to bring low down to 0.8V, but as high only have to be 1.37V, use resistor divider.
    If you already have a 200K pull-down, a 100K series resistor would make it a resistor divider that should be within specs