General
Review and verify the following for
the custom schematic design:
- The sections above, including relevant
application notes and FAQ links.
- PMIC selection (orderable part number).
- 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.
- Provision to configure core voltage using
GPIO3.
- Connection of analog inputs to PMIC ADC inputs
GPIO4 or GPIO5.
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.
- Core voltage
configuration using GPIO3 (BUCK1,2 High: 0.85V,
Low/Floating: 0.75V), VDD_CORE and VDDR_CORE sequencing, and
provision for alternate core voltage configuration.
- 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.
- PMIC nRSTOUT slew
(pullup value) when connected directly to processor MCU_PORz
input (recommend using a discrete push pull buffer).
- 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.
- External
Implementation of SD card supply supporting UHS-I speed and
eFuse programming VPP supply.
- Connection of
interrupt, EN/PB/VSESNSE and sleep signals and pulls for the
IOs.
- Connection of
analog inputs and input range for GPIO4 or GPIO5.
Additional
- For power architectures based on a TI PMIC
design, conduct a detailed review of the implementation with
the PMIC BU or 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.
- 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.