A x e l H a r d w a r e M a n u a l
v . 1 . 0 . 4
NVCC_EIM_EXT, NVCC_SD3_EXT,
NVCC_LCD_EXT) are powered by carrier board
10. PMIC VGEN6 LDO is turned on (this is the last
regulator turned on automatically by PMIC)
11. CPU_PORn is released.
5.1.1
Note on NVCC_AXEL_I/O_3.3V/1.8V (BOARD_PGOOD)
usage
NVCC_AXEL_I/O_3.3V/1.8V is generally used on carrier board
to drive loads such as DC/DC enable inputs or switch on/off
control signals. Depending on the kind of such loads,
NVCC_AXEL_I/O_3.3V/1.8V might not be able to drive them
properly. In these cases a simple 2-input AND port can be used
to address this issue. The following picture depicts a principle
schematic showing this solution. VDD_SOM denotes the power
rail used to power AXEL ULTRA SoM.
5.1.2
Note on NVCC_EIM_EXT
If the SPI NOR flash is mounted on the AXEL ULTRA SoM, the
NVCC_EIM_EXT input signal can't be configured as an
extended range voltage, but it must be connected to a +3.3V
rail (because the SPI bus used internally for the NOR flash
shares some pins of the EIM bank).
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NVCC_AXEL_I/O_3.3V/1.8V
PMIC_PWRON
SOM_VDD
- DC/DC
ENABLE
- SWITCH
ON/OFF
- …..
