One of my medical customers who is using a RT64 is also looking for the GPIO max sinking and sourcing current specification for documentation purposes. Please let me know where I can find this info.
I searched in both the DS and RM but there are no such data. Please advise!
GPIO DC parameters in i.MX Datasheet(s) provide typical Ioh and Iol values.
Generally the GPIO drive current is affected by the configuration of the buffer. Customers
can use DSE field in the controlling IOMUX registers to set the drive strength. There are also
a slew rate controls in those registers which may also have an effect
i.MX RT 1064 Datasheets contain “GPIO output buffer average impedance” tables. Parameter Output
Driver Impedance allows to estimate
1) max possible (short circuit) current, as following: I = Vout / Impedance (143 mA =3.3V / 23 Ohm);
2) real current, depending on external load; I = Vout / (Impedance+R_load), so to get 10mA, external
load of ~300 Ohm is needed, assuming DSE =111.
Of course it is needed to take into account thermal considerations in order to avoid device damage.