GPIO output source resistance

RE: GPIO output source resistance

MARTIN FR — Mon, 07 Dec 2015 08:56:38 GMT

can i connect two gpio to a single buzzer sot hat my current will be 10mA in the positive terminal of the buzzer ? becuase i ahve ssen in datasheet it is mentioned maximum drive curretn 5MA on single GPIO pin so can you give me some clarification about this point

RE: GPIO output source resistance

Håkon Alseth — Thu, 01 Oct 2015 11:13:59 GMT

NP, always happy to help! :-)

RE: GPIO output source resistance

Rushd — Wed, 30 Sep 2015 21:35:32 GMT

Thanks a bunch!

RE: GPIO output source resistance

Håkon Alseth — Wed, 30 Sep 2015 12:58:46 GMT

Hi,

We do not have specification for this parameters, but by looking at the guaranteed voltage area for the output, you can do some simple calculation to find the resistance.

In both "High" and "Standard", we guarantee that the voltage shall be within VDD-0.3V when setting the output.

The equivalent resistance can then be calculated:

Re = delta(U) / I

For "Standard" 0.5 mA:

Re = 0.3 V / 0.0005 A = 600 ohm

For "High" 5 mA:

Re = 0.3 V / 0.005 A = 60 ohm

Cheers, Håkon