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 architecture supports active discharge
- Slew rate of discrete DC/DC outputs connected to
the processor meets the processor supply slew requirements and sequencing of
all the supply rails as per the processor requirement
- PORz input (PG output) slew rate (connect through discrete push-pull output buffer) and L to H delay (PORz input low 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)
- Discrete DC/DC or LDO device selection including
output voltage level and current rating, active discharge capability,
residual voltage detection (Allow to power-up only when the supply voltages
are < 0.3V after power-down)
- Implementation of SD card interface IO supply supporting UHS-I SD card and eFuse programming VPP supply
- Naming of the supply rails (indicate configured output voltage level)
- Matching of the discrete DC/DC or LDO output
voltage levels with the supply requirements (ROC) for the processor and
attached devices
- Supply net names matches (same name) for processor and attached devices IO supplies
Schematic Review
Follow the below list 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 discrete DC/DC or LDO EN for supply sequencing
- Discrete DC/DC or LDO outputs slew rate
- PORz input low hold time after supplies ramp, in
case the discrete DC/DC PG output connects directly to the processor PORz
input
Additional
- In case the power architecture is based on TI
power, obtain a review of the implementation done
with the relevant business unit or product
line
- A 0Ω resistor or jumper is recommended at the output of the supply rails for isolation or current measurement for the initial board build. Select resistors that are rated for the supply rail current