To limit the input voltage, I put 10k ohm series register and two diodes before the input of AD8542.Voltage at the input pin is limited between -0.7V and +5.7V.Does +5.7V input voltage cause damage to AD8542 which operates with Vs=+5.0V ?How about -0.7V input voltage ?Data sheet tells Absolute maximun rating of input is 0V to Vs.But Figure 31. No Phase Reversal shows the example that input voltage goes higher than Vs and lower than GND.Could you give me advice ?Thank you.
I would switch to Shottky diodes to limit the swing to -0.3V to 5.3V. That way, the internal ESD diodes will not
Fig. 31 is deliberate abuse to show you that the part does not phase reverse. (Don't try this at home.)
You have to follow the abs max table and the spec table.
Thanks for your comment.
I tried Shottky diodes and found they have large leakage current.
I wonder why data sheet has an example exceeding the absolute maximum ratings.
Anyway, I choose OP291 instead of AD8542.
It will be fine except that the price is much higher, hi.