Power
Jetson AGX Xavier Series Product
DG-09840-001_v2.5 | 20
Figure 5-2.
Power Up Sequence – Power Button Case
CARRIER_POWER_ON
Power Button press or
similar power-on event
VDDIN_PWR_BAD_N
SYS_VIN_HV
Carrier Board Power
(VDD_1V8, VDD_3V3)
Module Power (i.e. Main
1.8V rail & others enabled at
power-on)
SYS_RESET_N
MODULE_POWER_ON
SYS_VIN_MV
Main power source
connected
VIN_PWR_ON
Note
: The signal VIN_PWR_ON shown in the power sequences is not a pin on the module. This
signal is used on the developer kit design to enable the SYS_VIN_HV and SYS_VIN_MV supplies.
The basic power off sequencing requirements is as follows:
Early in the controlled power down sequence,
SYS_RESET_N
is asserted and the 3.3V always
on regulator is powered off. This results in
CARRIER_POWER_ON
going lower soon after
SYS_RESET_N
is de-asserted. The carrier board is required to power off the supplies
associated with the module.
Once the carrier board power supplies are adequately powered off, the
MODULE_POWER_ON
signal can be de-asserted which starts the module power down.
If the main power rails (
SYS_VIN_HV/MV
) are to be powered off, the
VIN_PWR_ON
(if
implemented), can be de-asserted, disabling the main power rails or if
VIN_PWR_ON
is not
implemented, the rails can just be powered off.
VDDIN_PWR_BAD_N
should go active (low) once either of the main power rails go below an
acceptable level.
Note
: If the main power rails (SYS_VIN_HV/MV) are not powered off, it is possible for the system
to power on again depending on the state of the signals. If the system was powered down due to
a shutdown condition that is cleared, the system may power back on. Unless this is desired, a
means of keeping the module powered off should be provided. One way is to latch the state of
CARRIER_POWER_ON when it goes from high to low (module powered off) and using this to keep
MODULE_POWER_ON inactive (low).