SMT4214 Summit Microelectronics, Inc., SMT4214 Datasheet - Page 4

• Manufacturer Part Number: SMT4214
• Description: Expandable Four-rail Supply TRAKKER™ Controller
• Manufacturer: Summit Microelectronics, Inc.

be driven low by any under-voltage condition. RST#
will remain asserted for a reset timeout period, t
after the under-voltage condition has cleared.
reset input (MR#) low. RST# will remain low so long
as the MR# input is active and will remain low for t
after MR# returns high. The manual reset input is used
to drive the RST# output low and to enable write
operations to the configuration registers.
affect on any other outputs or device operations.
IRQ OPERATION (See Figure 3)
power-on operation; from when power is first applied
until the VI inputs and VO inputs are above their
programmed
configuration register, IRQ# will be driven low by any
under-voltage condition.
output is latched until cleared by removing the under-
voltage condition and asserting IRQ_CLR#. Refer to
Figure 3 for an illustration of the relationship of these
conditions and signals.
FORCE SHUTDOWN (See Figure 4)
either externally or internally. The FS# pin is always
configured as an I/O and will always be enabled. If the
FS# pin is taken low the VGATE outputs will
immediately be clamped to ground.
as an internally initiated function when an under-
voltage condition is detected. The force shutdown can
be initiated internally when an under-voltage condition
is sampled at the end of tracking or on an under-
voltage condition after tracking is complete. In either
case, the FS# pin will be driven low and latched until
either the power is cycled or the PWR_ON# pin is
toggled. Refer to Figure 4,for an illustration of the
basic relation between VI, VO, FS# and VGATE.
Summit Microelectronics, Inc
Figure 4. Timing relation between VI/VO, FS# out and VGATE and the relation between FS# in and VGATE
If enabled in the configuration register, RST# will
RST# can be forced low by driving the manual
The force shutdown function can be initiated
The force shutdown function can be configured
VI or VO
VGATEx
The IRQ# output is disabled throughout the
FS#
OUT
thresholds.
Internally triggered FS# action
P
VIT
Once asserted, the IRQ
t
DUVFS
t
DUVVG
If
enabled
It has no
in
PRTO
PRTO
the
2061 1.0 8/16/02
,
MULTI-DEVICE OPERATION
board if more than four supplies need to be monitored
and controlled. One SMT4214 must be configured as
the master and the others must be configured as
slaves. The device configured as the master must
have a supply voltage that is greater than or equal to
the supply voltages of its slave devices.
SMT4214 provides four signals for easy interfacing;
PWR_ON#, FS#, VRLINK and LINK#.
connected together on each of the SMT4214s to
coordinate the power-on and power-off operation.
PWR_ON# can be toggled by an external host or by
the master SMT4214 in response to a command
received on the I
device application must be tied together. One or more
of the SMT4214’s could be configured to generate a
force shutdown if an under-voltage condition is
detected.
VRLINK pin will be configured as an output; all other
devices in the system are slaves. As an output, the
VRLINK provides an analog signal that is the ramp
reference used to track the card-side voltages. The
slave devices will use this input as their own ramp
reference. In this manner, tracking between all of the
devices is coordinated.
power-on or power-off operation and all the devices
will have their LINK# pins connected together. It is
through this pin that the tracking function is
coordinated. As an example: device 1 is the master
and is supplying the ramp reference to devices 2 and
3. If Channel A of device 3 falls behind the ramp
reference, device 3 will assert its LINK# output thus
halting the ramp on the card-side voltages of devices
1, 2 and 3 until channel A of device 3 can catch-up.
The master and slave channels can be configured for
any combination of tracking, soft start or mixed.
VGATEx
FS#
Multiple SMT4214’s can be used on the same
PWR_ON# is an I/O.
FS# is an I/O, therefore, all FS# pins in a multi-
When a device is configured as a master its
The LINK# pin is an I/O that is used only during a
IN
t
DFSVG
Externally triggered FS# action
2
C bus.
Preliminary Information
This pin should be
SMT4214
The
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