How much voltages can FiO board stand?

It depends on usages.The table below specifies maximum voltages that STM32F4 MCU can stand. This depends whether the pins of STM32F4 MCU is 5V Tolerance or not.

(All information comes from STM32F417xx Datasheet. FOr those interested to study further can start at How to identify and use Microcontrollers’ pins, and How to Use Digital Input/ Output).

STM32F4 Absolute Maximum Rating

STM32F4 Absolute Maximum Rating

For 5V Tolerant, the maximum voltage is VDD+4V.

If NOT 5V Tolerant, the maximum voltage is 4V.

These are absolute maximum values that an MCU can stand. In real uses, lower values should be applied which can be divided into either:

  • Digital
  • Analog

For Digital Input, common values are as follows:

STM32F4 Digital Input Characteristics

STM32F4 Digital Input Characteristics

For Analog Input, the maximum is NO BIGGER than VREF+, which for FiO VREF+ is tied to VDD at 3.3V as shown in the table below.

STM32F4 ADC Characteristics

STM32F4 ADC Characteristics