TM4C1294NCPDT: GPIO injection current values

Franco Souza

Part Number: TM4C1294NCPDT

I'm confused as to what the values for "DC injection current, VIN ≤ 0 V" and "Max negative injection if not voltage protected" mean. These values are on table 27-34 of the TM4C1294NCPDT's datasheet, and I'm confused about how would a pin configured as GPIO behave when not voltage protected. I wanted to dimension current limiting resistors in these pins according to table Table 27-37, which contains max positive and negative current injection values. However, since these pins will be configured as GPIOs, now I'm not sure anymore.

over 6 years ago

0 Bob Crosby over 6 years ago

TI__Guru 72500 points

Choose a current limiting resistor, R, such that the maximum negative voltage applied to the resistor Vin_max_neg/R < 0.5mA, and the maximum input voltage (Vin_max_pos - Vdd) < 2mA. Make sure you include the case when Vdd = 0V.

0 Franco Souza over 6 years ago in reply to Bob Crosby

Prodigy 150 points

That's what I expected, thank you. But still, in this case, should I then ignore the values shown in the picture below? What do they mean exactly?

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TM4C1294NCPDT: GPIO injection current values