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 or 47kΩ) 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.