XRP7720 Datasheet, PDF (22/28 Pages) Exar Corporation – Quad Output Universal Customizable PMIC with PFM

XRP7720
Quad Output Universal Customizable PMIC with PFM
case the current drawn from Vcc supply will
be minimal.
If the function is not used, it is recommended
that the pin either be grounded or left
floating. in conjunction, the function must be
disabled through register settings.
V5EXT switchover control
The V5EXT function is enabled in PA 5.1. The
switchover thresholds are programmable in
50mV steps with a total range of 200mV. The
V5EXT switchover has a 150mV hysteresis.
LDO5 automatically turns off when the
external voltage is switched in and turns on
when the external voltage drops below the
lower threshold.
Channels can be controlled independently by
any GPIO/PSIO. Channels will start-up or
shut-down following transitions of signals
applied to GPIO/PSIOs set to control the
channels. In development, using the
XRP7720ILB-DEV and PA 5.1, control can
always be overridden.
Regardless of whether the channels are
controlled independently or are in a group the
ramp rates will be followed as specified (see
the Power Sequencing section).
POWER SEQUENCING
All four channels can be grouped together and
will start-up and shut-down in a user defined
sequence.
Selecting none means channel(s) will not be
assigned to any group and therefore will be
controlled independently.
Group Selection
CHANNEL CONTROL
© 2014 Exar Corporation
There are three groups:
 Group 0 – is controlled by the chip
ENABLE. Channels assigned to this group
will come up with the ENABLE signal being
high (plus an additional delay needed to
load configuration from Flash to runtime
registers), and will go down with the
ENABLE signal being low.
Since it is recommended to leave the
ENABLE pin floating in the applications
when Vcc = LDO5 = 4.75V to 5.5V, please
contact Exar for how to configure the
channels to come up at the power up in
this scenario.
 Group 1 – can be controlled by any
GPIO/PSIO. Channels assigned to this
group will start-up or shut-down following
transitions of a signal applied to the
GPIO/PSIO set to control the group.
 Group 2 – can be controlled by any
GPIO/PSIO. Channels assigned to this
group will start-up or shut-down following
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Rev. 1.0.0