TMS320F28377D: GPIO input current

Luke Chen

Part Number: TMS320F28377D

Hi Champs,

In F28377D datasheet, the GPIO input current with internal pullup enabled is 150uA, is this 150uA an input or output current?

Please advise, thanks.

Luke

over 7 years ago

0 Nima Eskandari over 7 years ago

TI__Guru 52040 points

This is the input current. The GPIO is configured as input in this case.

0 Luke Chen over 7 years ago in reply to Nima Eskandari

TI__Expert 5090 points

Hi Nima,

When the condition is VDDIO = 3.3V and VIN = 0V.
Do you mean this 150uA input current is the current through internal pull-up resistor from VDDIO? Or do you mean GPIO will sink 150uA from outside of C2000 when VIN = 0V?

Regards,
Luke

0 Nima Eskandari over 7 years ago in reply to Luke Chen

TI__Guru 52040 points

The active component inside the device that acts as a pull up resistor, won't sink or source much current when there is nothing connected. But let's say that the Pull up is enabled and the pin is shorted to ground, then the internal pull up will have a 150uA current going out of the pin. It is trying to fight to keep a logic high on the pin but it is overpowered since it cannot do more than 150uA so the GPIO will be logic low.

0 Luke Chen over 7 years ago in reply to Nima Eskandari

TI__Expert 5090 points

Nima,
As you mentioned, when the pull up is enabled and the pin is shorted to GND, then the internal pull up will have a 150uA current going out of the pin.
So, this should be an output current, not an input current. Is it correct?

Luke

0 Nima Eskandari over 7 years ago in reply to Luke Chen

TI__Guru 52040 points

Yes the current will be flowing out of the device.

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TMS320F28377D: GPIO input current