D J

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8 years, 1 month ago.

NUCLEO F091RC current per io

Can someone please tell me what is the max current output from any I/O of this board and what is the total current which mcu will support from its I/O's before it goes beyond it's max current drain limit

1 Answer

Jan Jongboom
8 years, 1 month ago.

From the datasheet (page 82):

Quote:

The GPIOs (general purpose input/outputs) can sink or source up to +/-8 mA, and sink or source up to +/- 20 mA (with a relaxed VOL/VOH).

In the user application, the number of I/O pins which can drive current must be limited to respect the absolute maximum rating specified in Section 6.2:

  • The sum of the currents sourced by all the I/Os on VDDIOx, plus the maximum consumption of the MCU sourced on VDD, cannot exceed the absolute maximum rating ΣIVDD (see Table 21: Voltage characteristics).
  • The sum of the currents sunk by all the I/Os on VSS, plus the maximum consumption of the MCU sunk on VSS, cannot exceed the absolute maximum rating ΣIVSS (see Table 21: Voltage characteristics).

Check that section of the datasheet for more information.

Thanks for your answer! Just to understand it properly, I have one question if I may ask please - Source and sink currents are given as two different sums, so if I have 12 pins pulled upto 3.3v (generated by the nucleo board itself) by 4.7k external resistors and 110mA output current to drive optos as outputs - will it work! Can I use this board for such a task? Thanks!

posted by D J 29 Mar 2016

I wouldn't know. I'd ask a new question and tag it with the board name, ST people are reading as well.

posted by Jan Jongboom 30 Mar 2016