I'm a bit confused about input pin voltage tolerances and output pin voltage values of ICs.
I would think that datasheets for ICs that involve signal inputs/outputs would list two values:
- The maximum voltage for a signal HIGH that it can tolerate at an input pin.
- The minimum voltage for a signal HIGH that it will set at an output pin .
But many datasheets don't appear to list them for all pins. For example, I'm experimenting with STM6600, and its datasheet doesn't provide them; see below:
Above, "PB" is an input; "EN" and "INT" are outputs. Notice that only EN's minimum HIGH output is provided, but neither INT's minimum HIGH output nor PB's maximum HIGH input is provided.
Thus, I'm unsure about what to do in this situation.
Let's say I set VCC = 3.0V on this IC.
Then how do I determine:
Will this IC (STM6600) tolerate a given input signal HIGH from a different IC running at, e.g., a higher VCC = 3.3V?
And correspondingly, will a given output signal HIGH from this IC (STM6600) cause damage to a different IC running at, e.g., a lower VCC = 2.7V?
Even if the answer to these questions is No, I would still be interested in knowing the actual numerical values that I should expect, hence my problem with the datasheet.