General
Review and verify the following for the custom schematic design:
- Reviewed above "Common
checklist for all sections" section of the user's guide.
- Provision for series resistors added for all the interface signals near to
the source.
- Provision for parallel pull added for the processor or attached device
interface IOs.
- Connection of IO supply for IO group and attached device IO supply.
- Fail-safe operation of MCAN interface signals.
Schematic Review
Follow the below list for the custom schematic
design:
- Series resistor value used (22Ω) and the placement (near to source).
- Parallel pull value (10kΩ) added for any of the processor or attached device
IOs that can float (to prevent the attached device inputs from floating
until driven by the host).
- Pullup referenced to (powered by) the processor VDDSHVx for corresponding
MCAN instance and pins matches.
- Supply rails connected to the IO supply for IO group VDDSHVx referenced to
(powered by) MCAN peripherals and attached devices IO supply are connected
to the same power source and follow the ROC.
- Provision for parallel pull
added for any of the processor or attached device IOs that can float.
- MCAN interface signals are not fail-safe. The recommendation is to apply the
inputs only after the processor supply ramps.
Additional
- Processor IOs are not fail-safe. No external input is recommended to be
applied before the processor supply ramps. The recommendation is to verify
fail-safe operation when connected to external interface signals. Applying an
external input signal to the processor MCAN inputs before processor supply ramps
can cause voltage feed and can affect the custom board functions.
- External ESD protection when the
interface signals are connected directly to external inputs.