NXP Semiconductors QorIQ LS1028A, Reference Manual, Page: 19 / 112

Table 4. Secondary power supplies (continued)
Part
identifi
er Manufacturing
part number Part
manufacturer Power
supply Specifications Description
U7 FPF1321UCX ON
Semiconductor EVDD
3.3 V
1.8 V
eSDHC IO Power.
EVDD boots up to
3.3 V and can be
changed to 1.8 V
depending upon the
SD_VSEL pin state
that is controlled
from the LS1028A
SDHC IP block.
NOTE
The FPF1321UCX
is a power switch,
not a power supply.
NOTE
.
U8 MAX8902B Maxim
Integrated TA_BB_V
DD 0.9 V / 1.0 V at 0.15
A Power supply for TA_BB_VDD.
1. VDD is 1.0 V or 0.9 V depending upon the state of GPIO1_DAT24 GPIO pin of LS1028A.
2.2.3 Power supply sequence
The LS1028ARDB board is configured to switch ON automatically when the 12 V power supply is switched ON and is connected
to jack (J1) on the board.
The 12 V input can be subsequently power cycled using the following events:
• The power switch (push button) is pressed
• The register bit, PWR_CTL2[PWR], is set to ‘1’ using the I2C or JTAG/CCS communication paths
On the availability of 12 V supply to the power regulators, the orderly enable of all power supplies are sequenced using powergood
of the regulators, as shown in the following figure.
Power supplies
QorIQ LS1028A Reference Design Board Reference Manual, Rev. b, 11/2018
NXP Semiconductors COMPANY CONFIDENTIAL
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