Max pin output current limit

[javida14]

Posted on December 12, 2006 at 12:08

Max pin output current limit

[javida14]

Posted on December 11, 2006 at 21:13

The STR730 part has a source/sink capability of 2ma. if an output pin is in a logic high state and the pin is accidently shorted to ground will this destroy the pin or is the output internally limit to 2ma?

Javi

[kleshov]

Posted on December 12, 2006 at 02:59

There is no internal current limiting. Current will be limited by ON-resistance of the open transistor. Based on the 2mA figure, short circuit current could be around 10mA. It is unlikely to destroy the I/O pin, but you shouldn't take the risk.

Regards,

- mike

[javida14]

Posted on December 12, 2006 at 12:08

Thanks Mike,

The position of a rotary switch is being determine by connecting 8 outputs to the switch and the wiper to an input pin. A zero in a pattern of ones is being walk to determine the switch position. Just wandering if an IC buffer should be used in the outputs or not in case of a potential short in the external logic just to protect the uP.

Javi