STM32F 5V to open drain pin

• STM32F 5V to open drain pin
  Posted by Vindhyachal.takniki on 23 Apr, 2015 12:59
• 1. I am using stm32f205.
  2. MCU is powered by 3.3V.
  3. Another ic pin is driven by 5V logic or (Vih = 0.7*VDD = 3.5V)
  4. Can I set pin of STM32F2 as open drain & connect 5V by pull up to it.
  5. Datasheet of MCU says that they are not true open drain pins.
• #1 Reply
  Posted by mrflibble on 23 Apr, 2015 13:11
• The pins marked as 5 Volt tolerant (FT) should be able to act as an open drain connected to a 5 Volt rail. As long as you use an external pullup (as opposed to the internal weak pullup), and keep the current limited you should be fine.