The recommendation is to add a series resistor (with a value that is use case dependent) to limit the current. Externally buffer the GPIO outputs when higher (above the data sheet specified value) current sourcing is required.
Common processor LVCMOS IO interface
guidelines:
- Most of the processor IOs are not
fail-safe. No input can be applied before supply ramps.
- Processor LVCMOS IOs have slew
rate or slew requirements (<1000ns) specified, applying a slow ramp input or
connecting a capacitor directly at the input is not recommended.
- Connecting a capacitor load >
22pF at the output is not recommended. DNI capacitor or perform simulations
based on the use case.
- Processor IO buffers are off
during reset. A pull is recommended near to the attached device being driven by
the processor IO that can float.
- A parallel pull is recommended
for any processor IO pad that has a trace connected. When adding pull is not
feasible, route the traces away from noisy signals.
- Verify IO compatibility and
fail-safe operation between the processor and attached devices IOs.