General
Review and verify the following for
the custom schematic design:
- Above sections, including
relevant application notes and FAQ links
- PMIC selection (orderable
device) based on the input supply, core voltage, IO voltage and DDR voltage
configuration
- PMIC checklist for addition
of required input and output capacitors including values, feedback
configuration, and pin connections
- Voltage rating of the
selected capacitors considering derating (twice the worst-case applied
voltage is a commonly used guideline)
- Configuration of the
recommended PMIC control and IO signals
Schematic Review
Follow the below list for the custom
schematic design:
- Compare the custom PMIC
implementation with the SK schematic implementation for capacitors and
values, IOs connections, and DC/DC output feedback connection
- Processor to PMIC and PMIC to
processor IO interface connections
- Connection of the required
control signals for processor IO supply sequencing (load switch EN for
processor and attached device IO supply voltage and slew rate control)
- Processor and PMIC I2C
interface used versus recommend, considering the use case
- SD card IO voltage control
configuration pin connection (3.3V during start-up and switched to 1.8V),
verify the VSEL_SD configuration based on SD card interface use case
- PMIC nRSTOUT slew (pullup
value) when connected directly to processor MCU_PORz input (recommend using
a discrete push pull buffer)
- Connection of interrupt,
MODE/RESET, and EN/PB/VSENSE signals and pulls for the IOs
- Configuration of other
discrete DC/DC supplies and LDOs used along with the PMIC
- VPP supply (eFuse
programming) external LDO implementation, output control and addition of
bulk and decoupling capacitors considering load current transient and
provision for isolation resistor for testing the VPP enable timing
Additional
- In case power architecture is
based on TI PMIC solution, get detailed review of the power architecture
implementation done with the PMIC BU/PL.
- A 0Ω resistor or jumper is
recommended at the output of the supply rails for isolation or current
measurement for the initial board build.
- Since the PMIC performs a warm
reset, connecting the RESETSTATz output from the processor to the MODE/RESET
input of PMIC can lead to ineffective reset behavior. A 0Ω resistor and DNI are
recommended, and internal pull-up is available.
- Show the PMIC input bulk
capacitors connection for DC/DC inputs and VSYS separately and near to the pins
for ease of placement and routing.