FGSD12SR6003A Datasheet, PDF (16/41 Pages) List of Unclassifed Manufacturers – 3-14.4Vdc Input, 3A, 0.45-5.5Vdc Output

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FGSD12SR6003*A
3-14.4Vdc Input, 3A, 0.45-5.5Vdc Output
VOUT_UV_FAULT_LIMIT sets the threshold that
causes an output under voltage fault and can also be
selected from four possible values: 92%, 90%, 88%
or 85%. The default values are 112% and 88% of
commanded output voltage. Both commands use two
data bytes formatted as two’s complement binary
integers. The “Linear” mode is used with the
exponent fixed to –10 (decimal) and the effective
over or under voltage trip points given by:
V_{OUT(OV _ REQ)}  (VOUT _ OV _ FAULT _ LIMIT )  2^10
V_{OUT(UV _ REQ)}  (VOUT _ UV _ FAULT _ LIMIT )  2^10
Values within the supported range for over and
undervoltage detection thresholds will be set to the
nearest fixed percentage. Note that the correct value
for VOUT_SCALE_LOOP must be set in the module
for the correct over or under voltage trip points to be
calculated.
In addition to adjustable output voltage protection, the
3A Digital Tomodachi module can also be
programmed for the response to the fault. The
VOUT_OV_FAULT_RESPONSE
and
VOUT_UV_FAULT_RESPONSE commands specify
the response to the fault. Both these commands use
a single data byte with the possible options as shown
below.
1. Continue operation without interruption
(Bits [7:6] = 00, Bits [5:3] = xxx)
2. Continue for four switching cycles and then shut
down if the fault is still present, followed by no
restart or continuous restart
(Bits [7:6] = 01, Bits [5:3] = 000 means no restart,
Bits [5:3] = 111 means continuous restart)
3. Immediate shut down followed by no restart or
continuous restart
(Bits [7:6] = 10, Bits [5:3] = 000 means no restart,
Bits [5:3] = 111 means continuous restart).
4. Module output is disabled when the fault is
present and the output is enabled when the fault
no longer exists
(Bits [7:6] = 11, Bits [5:3] = xxx).
Note that separate response choices are possible for
output over voltage or under voltage faults.
PMBus Adjustable Input Undervoltage
Lockout
The module allows adjustment of the input under
voltage lockout and hysteresis. The command
VIN_ON allows setting the input voltage turn on
threshold, while the VIN_OFF command sets the
input voltage turn off threshold. For the VIN_ON
command, possible values are 2.75V, and 3V to 14V
in 0.5V steps. For the VIN_OFF command, possible
values are 2.5V to 14V in 0.5V steps.
Preliminary Data Sheet
If other values are entered for either command, they
will be mapped to the closest of the allowed values.
VIN_ON must be set higher than VIN_OFF.
Attempting to write either VIN_ON lower than
VIN_OFF or VIN_OFF higher than VIN_ON results in
the new value being rejected, SMBALERT being
asserted along with the CML bit in STATUS_BYTE
and the invalid data bit in STATUS_CML.
Both the VIN_ON and VIN_OFF commands use the
“Linear” format with two data bytes. The upper five
bits represent the exponent (fixed at -2) and the
remaining 11 bits represent the mantissa. For the
mantissa, the four most significant bits are fixed at 0.
Power Good
The module provides a Power Good (PGOOD) signal
that is implemented with an open-drain output to
indicate that the output voltage is within the
regulation limits of the power module. The PGOOD
signal will be de-asserted to a low state if any
condition such as overtemperature, overcurrent or
loss of regulation occurs that would result in the
output voltage going outside the specified thresholds.
The PGOOD thresholds are user selectable via the
PMBus (the default values are as shown in the
Feature Specifications Section). Each threshold is set
up symmetrically above and below the nominal value.
The POWER_GOOD_ON command sets the output
voltage level above which PGOOD is asserted (lower
threshold). For example, with a 1.2V nominal output
voltage, the POWER_GOOD_ON threshold can set
the lower threshold to 1.14 or 1.1V. Doing this will
automatically set the upper thresholds to 1.26 or
1.3V.
The POWER_GOOD_OFF command sets the level
below which the PGOOD command is de-asserted.
This command also sets two thresholds
symmetrically placed around the nominal output
voltage. Normally, the POWER_GOOD_ON
threshold is set higher than the
POWER_GOOD_OFF threshold.
Both POWER_GOOD_ON and
POWER_GOOD_OFF commands use the “Linear”
format with the exponent fixed at –10 (decimal). The
two thresholds are given by
V_{OUT(PGOOD _ON)}  (POWER _ GOOD _ ON)  2^10
V_{OUT(PGOOD _OFF)}  (POWER _ GOOD _ OFF )  2^10
Both commands use two data bytes with bit [7] of the
high byte fixed at 0, while the remaining bits are r/w
and used to set the mantissa using two’s complement
representation. Both commands also use the
VOUT_SCALE_LOOP parameter so it must be set
correctly. The default value of POWER_GOOD_ON
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Ver 1.6 May. 8, 2013