I would like to connect four output pins of a certain IC to four input pins of an AVR microcontroller (Atmega328).
I'm running the IC at VCC that varies between 3.50V and 4.00V. It outputs signals (for status indication) with an Output High spec of V_HIGH = VCC - 0.30, per the datasheet. Thus, in my case, minimum V_HIGH for an output signal from this IC will vary between 3.20V and 3.70V.
But I'm running my microcontroller at VCC = 3.30V, and I want it to read the inputs from the IC above (and not damage the microcontroller obviously).
What is a robust, hopefully simple, way to address this problem?
I am thinking perhaps a diode, to create a voltage drop, in series with each of the signals.