General
Review and verify the following for
the custom schematic design:
- Above sections, 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 VDDSHV4, VDDSHV5, VDDSHV6 for
AM62x VDDSHV4, VDDSHV5, VDDSHV6 for AM62Ax 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 below list 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 VDDSHV_MCU) supply only support a single
voltage level.
- Follow the processor-specific SK for implementation of ferrites and
capacitors.
- Leaving VDDSHV5 power supply rail unconnected is not recommended. Connect the
power pins to either 1.8V or 3.3V, depending on your preference for the voltage
level of the VDDSHV5 IO bank signals.