https://devzone.nordicsemi.com/f/nordic-q-a/19897/nrf51822-gpio-direct-source-with-high-drive-settingI directly connect GPIO pin with 24ohm resistor as follows. And I set GPIO pin as high drive, NRF_GPIO-&gt;PIN_CNF[MY_PIN_NO] |= (GPIO_PIN_CNF_DRIVE_H0H1 &lt;&lt; GPIO_PIN_CNF_DRIVE_Pos); When I measure the current, I got 38mA. But it should not exceeden-USTelligent Community 13Thu, 23 Feb 2017 03:42:57 GMThttps://devzone.nordicsemi.com/thread/77435?ContentTypeID=1Thu, 23 Feb 2017 03:42:57 GMT137ad170-7792-4731-bb38-c0d22fbe4515:99edb6f4-703b-48c9-9e34-668fb820c015sosse<p>Thank you!</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/77433?ContentTypeID=1Wed, 22 Feb 2017 11:39:34 GMT137ad170-7792-4731-bb38-c0d22fbe4515:cafc1c7c-461e-4967-85b6-0de140ad87dcOle Bauck<p>24ohm * 38 mA ~= 0.9V, so you see that the output voltage will fall if the current goes up. The specification says that you can draw 5mA in high drive and the voltage will still be within VDD-0.3 and VDD. We recommend that you draw no more than 15mA in total as Roger says, this can be from one pin. If you draw more than this we can&#39;t guarantee that the chip will function properly.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/77434?ContentTypeID=1Wed, 22 Feb 2017 04:30:54 GMT137ad170-7792-4731-bb38-c0d22fbe4515:64049130-b5a3-4bbc-b99a-7faca13489e3Roger Clark<p>15mA is the maximum current you should draw from a pin (or the total of all pins)</p> <p>The nRF51822 (or any nRF5x device) will not limit the current on an output to 15mA.</p> <p>You are likely to damage the nRF51822 if you exceed the max GPIO current in the spec.</p> <p>220 ohms is approximately the lowest value resistor you could connect to a pin.</p><div style="clear:both;"></div>