I'm redesigning an automotive scanner tool. In the previous design, overvoltage problems were found in the digital communication lines that have pins exposed at the device connector with the external world. So, product modules can be attached to it. There are 11 pins in total, which can be either general purpose I/O or some protocol such as SPI, I2C and UART. The maximum data rate achieved on these lines would not be much higher than 1MHz.
Trying solve the issue, I found analog protection switches, such as the ADG5412F / ADG5413F switches. However, these switches, since using a single source, have a minimum supply voltage of 8V, that is too high, since the microcontroller I'm using cannot have more than 6V on its pins.
I would like to know if there is a similar solution, for detection and protection against overvoltage, but that can work to protect a IC that works with 5V logic.