Question

What is the difference of GPIO structure on Silicon Labs MCU families.

Answer

5V tolerance of GPIO pins on Silicon Labs MCU families as follows

• Pins are 5V tolerant across the normal operating power supply range.   When the power supply is 0V, the pins can tolerate 3.3V indefinitely, and they can tolerate 5V for brief periods (such as a hot-plug situation) without additional pin leakage.  Long-term exposure to 5V while the chip is unpowered may result in performance degradation or failure.
• Devices: F30x, F326. etc

Type B:

• Pins are tolerant of the IO power supply voltage plus 2.5V, so they are 5V tolerant with a 3.3V supply.  When the pin voltage rises more than 2V above the supply, the leakage currents from the pin to the supply and from the pin to ground will increase with voltage.  When the power supply is 0V, the applied pin voltage can be as high as 3.3V at room temperature with moderate leakage; but at that voltage, the leakage can be very high at elevated temperature.

• Devices: EFM8UB1, C8051F86x. etc

Type C:

• Pins cannot exceed the IO power supply voltage, which can be up to 5V. The pin includes an ESD protection diode to the power supply, so the pin leakage will increase exponentially if the pin voltage exceeds the power supply voltage by more than 0.5V at room temperature. These pins are 5V tolerant only if the IO supply is 5V..

• Devices: C8051F55x.

Type D:

• Pins cannot exceed the IO power supply voltage, which can be up to 3.3V.  The pin includes an ESD protection diode to the power supply, so the pin leakage will increase exponentially if the pin voltage exceeds the power supply voltage by more than 0.5V at room temperature; therefore they are not 5V tolerant under any conditions.
• Device: EFM8SB1, C8051F37x/39x. etc