General
Review and verify the following for the custom
schematic design:
- The sections
above, including relevant application notes and FAQ
links.
- Pin attributes,
signal description, and electrical specifications.
- Electrical
characteristics and additional available information.
- A valid fixed
supply source is connected to (VDDSHV_CANUART, VDDSHV_MCU,
VDDSHV0, VDDSHV1, VDDSHV2, VDDSHV3) all the IO supply groups
as per the ROC.
- A valid supply
(that can be dynamically changed) source is connected to
VDDSHV5, VDDSHV6 for AM62P IO supply group as per the
ROC.
- Slew rate
requirements for IO supply rails are followed.
- Internal LDO
output pins have the recommended capacitors connected
(across CAP_VDDSn pin and VSS).
- Power sequence
recommendations as per the processor data sheet are
followed.
Schematics Review
Follow the list below for the custom schematic
design:
- Connection of the
recommended capacitor to CAP_VDDSn pins and VSS.
- CAP_VDDSn
capacitor package (use the smallest possible (0201 or
greater package possible which is closest to 0201) package
to minimize loop inductance).
- Voltage rating of
the capacitor selected for the capacitance value to be in
the range 0.8 to 1.5μF including aging, temperature and DC
bias effect.
- All IO supply
rails have a valid supply irrespective of the use of the IOs
referenced to the IO supply group.
- Supply rails
connected follow the ROC.
- Each CAP_VDDSn
pin requires a separate 1μF capacitor connected with respect
to VSS (ground).
- Select CAP_VDDSn
capacitor with less the 1Ω ESR, keep the trace loop
inductance to < 2.5nH.
Additional
- For all supply rails, use a 0Ω
resistor or jumper for isolation or current measurement at the output of the
supply rails.
- When any of the VDDSHVx power
rails are sourced from the 3.3V supply, all IOs referenced to the IO supply
group VDDSHVx must operate at 3.3V levels. If a VDDSHVx power rail is sourced
from a 1.8V supply, all IOs referenced to the IO supply group VDDSHVx must
operate at 1.8V levels.
- Some interfaces span multiple
VDDSHVx IO supply groups, for example MMC2 and GPMC. When using one of the
interfaces, all VDDSHVx domains supporting a specific interface need to share
the same voltage source.
- Most processor IOs are not
fail-safe. Applying input voltage to the IOs while the corresponding IO power
domain (VDDSHVx) is off is not allowed or recommended.
- Verify all IO pins on each
VDDSHVx (or MCU_VDDSHVx) supply only support a single voltage level.
- Follow the processor-specific SK
for implementation of ferrites and capacitors.