When selecting or designing the
processor power architecture, the recommendation is to consider the below listed
guidelines:
- The current (power)
requirement for each of the supply rail varies based on the interfaces used
and the operating environment.
- The current draw of processor
supply rails is estimated using the Power Estimation Tool (PET) for a
specific use case.
- If the supply rail powers the
other on-board attached (peripheral) devices, include the maximum current
draw of the attached devices for sizing the supply rail.
- For power supply sizing and
information on the maximum current rating for processor supply rails, see
the AM62x Maximum Current Ratings. The
recommendation is to frequently check the relevant processor product page
for availability of updated document.
- The recommendation is to
verify the output current ratings of the selected power architecture
(including PMIC, discrete DC/DCs and discrete LDOs) meet the maximum current
ratings of the selected processor and attached devices. The recommendation
is to add additional margins for design or manufacturing variances.
- The recommendation is to
verify if the power supply sequence (power-up and power-down) and supplies
slew rate follows the processor-specific data sheet. For the recommended
power sequencing requirements, refer to the Power Supply Sequencing
section of processor-specific data sheet.
For more information about processor
Recommended Operating Conditions (ROC), see the following FAQ:
[FAQ] AM625 / AM623 / AM620-Q1 / AM62Ax /
AM62D-Q1 / AM62Px / AM62L / AM64x / AM243x Design Recommendations / Custom board
hardware design – SOC ROC Recommended Operating Condition
Below are some guidelines to consider
when selecting or designing the processor power architecture:
- Supply rails are configured
to the required operating voltage level and the supply outputs are within
the processor ROC.
- Power architecture follows
the power-up and power-down sequence as specified in the processor-specific
data sheet.
- Power architecture meets the
slew rate requirements specified for the supply rails in the
processor-specific data sheet.
- All the power supplies
ramp-up and are stable before the MCU_PORz input is released
(deasserted).
- The delay between the
processor power supplies ramp up and the MCU_PORz input high follows the
processor-specific data sheet recommendations (9.5ms min).
- The recommendation is to make
sure the supplies are enabled only when the supply voltages ramp-down below
300mV (no residual voltage) during cold reset.
- All the supply rails decay
below 300mV (There is no time or decay voltage tolerance associated with the
requirement) before any of the power rail is allowed to ramp up after a
power cycle.
- MCU_PORz input slew is
minimum to avoid internal reset circuit glitch (the recommendation is to
connect the MCU_PORz input through discrete push-pull output type buffer
with minimum slew).
For information on residual voltage
and detection, see the following FAQ:
[FAQ] AM625 / AM623 / AM620-Q1 / AM62L / AM62A /
AM62P / AM62D-Q1 / AM64x / AM243x Design Recommendations / Custom board hardware
design – Queries related to Residual Voltage, Detection and supply
decay
Note:
Read the note at the start of Pin Connectivity Requirements section of the
processor-specific data sheet for connecting the supply rails and processor
signals named RSVD.