This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

CC2540 IO Sink capability

Other Parts Discussed in Thread: CC2540, CC2530


What is the CC2540's IO sink capability?

Could I sink 20mA from a LED?

I have been unable to find it in the documentation.

Best regards,


  • Hi Klaus,

    This information is found in the CC253x/CC2540 User Guide chapter 7.3. All GPIO pins can sink/source 4mA. P1.0 and P1.1 have extra drive strength and can sink/source 20mA.

    Remember to set PICTL.PADSC to 1 if your supply voltage gets below 2.6V. (chapter 7.2).



  • Hi Klaus,

    The I/O capabilities are documented in the datasheet on page 15:, but I agree that there's some information missing there. The table lists threshold voltages for the 4 mA output pins, but not for the 20 mA output pins (P1.0 and P1.1). They are mentioned on the pin list on page 17, however.

    These pins are identical to the ones of CC2530, which does list the threshold voltages (on page 17 of the CC2530 datasheet):, you can see that they will both sink and source 20 mA.

    Best regards,