Spirit1: DC-DC output for supplying external circuit

[kdudek67]

Posted on March 05, 2014 at 10:47

Dear ST,

Can I use the DC-DC output for supplying external circuit? If so how much current can be drawn? If not how much current can be drawn from GPIO pins?

[Nickname1920_O]

Posted on March 05, 2014 at 11:30

Hi Karol,

it is not recommeded to use SMPS to power external loads since this area is very senstive for the radio operation. In practice it should be OK to draw few mA, but not recommended. In addition the SMPS is not always active; for example it is off in SHUTDOWN, SLEEP, STANDBY and READY.Regarding the GPIO, the maximum current that can be drawn is: 

• 2.4 mA in low power mode 
• 4.2 mA in high power mode

Gaetano