Hello.
Please tell me about the case where the undershoot is below -0.5V.
Not found on the datasheet.
If the input waveform is -0.5V or less, are there any relaxation conditions according to the time regulation?
For example
If the input voltage below -0.5V is 20ns or less, up to -1.0V is acceptable.
Such
Regurd,
Hirofumi Yamaguchi
Hi Hirofumi,
There is no time dependency on the absolute max/min voltages. However if the current magnitude is clamped to < 50mA you can undervolt the IC below specs. This is shown in the absolute maximum ratings table. I/O Port clamp diode can take a max current magnitude of 50mA. If you read note 3 the voltage ratings can be exceeded if the clamp diodes have current clamped.
A current limiting resistor can be used to limit the current. For your application to size the resistor you assume the input pin is 0V and on the other side of the resistor is the minimum voltage V. The resistor can be found R = V/-50mA, so if the minimum voltage is -1V than the resistor needs to be at least 20 Ohms. Since the clamp will clamp below 0V (depending on current) the resistor approximation will slightly be a slightly overestimation, but this extra margin helps prevent damage from coming to the part.
If you have any other questions please let me know!
Best,
Parker Dodson
