How much current can a I/O pin sink

[Alvaro]

Hi everyone,

My question is how much current it´s capable to sink an I/O pin configured as output ´0´ ?

In my case I have to discharge a capacitor throught an output pin set to 0, and i would like to know how much current can it sink without burning or destroy anything.

Thanks.

[Håkon Alseth]

Hi,

By default, you can sink/source 0.5 mA on a GPIO. However, if you enable high-drive, you can sink up to 15 mA (max, combined on all GPIOs configured with high-drive):

NRF_GPIO->PIN_CNF[pin_number] = 
(GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos)| 
(**GPIO_PIN_CNF_DRIVE_H0H1** << GPIO_PIN_CNF_DRIVE_Pos)| 
(GPIO_PIN_CNF_PULL_Disabled << GPIO_PIN_CNF_PULL_Pos)| 
(GPIO_PIN_CNF_INPUT_Connect << GPIO_PIN_CNF_INPUT_Pos)| 
(GPIO_PIN_CNF_DIR_Output << GPIO_PIN_CNF_DIR_Pos);

H0H1 indicates high-drive on both logic '1' and '0'.

Best regards Håkon

[Alvaro]

So that´s means that I can have one pin configured with high-drive and sink up to 15 mA ( if I only have one pin high-drive configured) ?

Or only can sink 5mA each pin, with a maximum of 3 pin with high-drive configured?

Sorry if my question sound a little bit stupid, but I want to be sure.

[Håkon Alseth]

No worries. You can combine this, for instance have one that draws 10 mA + one that draws 5 mA, as long as you do not exceed the Itotal of 15 mA.

[Alvaro]

Thanks for the fast answer. :D