XRP7724 Datasheet, PDF (19/29 Pages) Exar Corporation – Quad Channel Digital PWM/PFM Programmable Power Management System

XRP7724
Quad Channel Digital PWM/PFM
Programmable Power Management System
SUPERVISORY AND CONTROL
Power system design with XRP7724 is
accomplished using PowerArchitect™ design
tool version 5 (PA5). All figures referenced in
the following sections are taken from PA5.
Furthermore, the following sections reference
I²C commands. For more on these commands
please refer to ANP-38.
DIGITAL I/O
XRP7724 has two General Purpose Input
Output (GPIO) and three Power System Input
Output (PSIO) user configurable pins.
 GPIOs are 3.3V CMOS logic compatible
and 5V tolerant.
 PSIO configured as outputs are open
drain and require external pull-up
resistor. These I/Os are 3.3V and 5V
CMOS logic compatible, and up to 15V
capable.
The polarity of the GPIO/PSIO pins is set in
PA5 or with an I²C command.
Configuring GPIO/PSIOs
The following functions can be controlled from
or forwarded to any GPIO/PSIO:
 General Output – set with an I2C
command
 General Input – triggers an interrupt;
state read with an I2C command
 Power Group Enable – controls
enabling and disabling of Group 1 and
Group 2
 Power Channel Enable – controls
enabling and disabling of a individual
channel including LDO3.3
 I²C Address Bit – controls an I2C
address bit
 Power OK – indicates that selected
channels have reached their target
levels and have not faulted. Multiple
channel selection is available in which
case the resulting signal is the AND logic
function of all channels selected
 ResetOut – is delayed Power OK. Delay
is programmable in 1msec increments
with the range of 0 to 255 msecs
 Low Vcc – indicates when Vcc has fallen
below the UVLO fault threshold and
when the UVLO condition clears (Vcc
voltage rises above the UVLO warning
level)
 Interrupt – the controller generated
interrupt selection and clearing is done
through I²C commands
Interrupt, Low Vcc, Power OK and ResetOut
signals can only be forwarded to a single
GPIO/PSIO.
In addition, the following are functions that
are unique to GPIO0 and GPIO1.
© 2012 Exar Corporation
19/29
Rev. 1.0.1