I've been looking at input protection circuits and I came across to some circuits that look like this one. Which is just based on the series resistor R1 to limit the current that flows through the MCU pin and also uses the Diodes D1 and D2 (D1 in this case) to release the excessive voltage to the power rail V1.
The question is about permanent voltage levels at 24V not transient effects or more higher than MCU pin levels.
Wouldn't that hurt the power rail (V1)? Even if diodes were omitted it would somehow hurt the power rail through MCU internal diodes. Wouldn't that make LDOs or DC to DC power supplies stop supplying power to the system due to the excessive voltage level and cause damage to the circuit?
I would lower the input voltage at a normal level and wouldn't use such circuit as a voltage translation.
Many other designs just suggest the same, a series resistor with a pair of diodes to both power rails. Some others just add a pull-up to MCU positive rail. And my understanding is that circuits like that are not meant to be used for voltage translation but only for ESD protection or transient responses. Am I missing something regarding to similar designs that could be found online?