General
Review and verify the following for
the custom schematic design:
- Above section, including relevant application
notes.
- The configured output voltage and the required
current rating for all the supply rails.
- Output voltage feedback connection and feedback
divider resistors tolerance.
- Selected discrete DC/DC design supports active
discharge.
- Slew rate meets the processor requirements and
sequencing of all the supply rails as per the
processor requirement.
- MCU_PORz slew rate (connect through discrete push
pull buffer) and L to H delay ( MCU_PORz hold time)
implementation after all the supplies ramp.
- Voltage rating of the selected capacitors
considering derating (twice the worst-case applied
voltage is a commonly used guideline).
- Device selection.
- Implementation of SD card interface IO supply
supporting UHS-I speed and eFuse programming VPP
supply.
Schematic Review
Follow the list below for the custom schematic
design:
- The resistor
divider value including tolerance connected to the feedback
input to generate the required output supply voltage matches
with the calculated value.
- PG outputs have
the required pullup and connects to the other DC/DC or LDO
EN for supply sequencing.
- Supply rails
output slew rate.
- MCU_PORz hold
time after supply ramp, in case the DC/DC PG output connects
directly to the processor MCU_PORz input.
Additional
- In case power architecture is based on TI power
designs, get detailed review of the power architecture
implementation done with the relevant 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