FGSD12SR6003A Datasheet, PDF (17/41 Pages) List of Unclassifed Manufacturers – 3-14.4Vdc Input, 3A, 0.45-5.5Vdc Output

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Series
FGSD12SR6003*A
3-14.4Vdc Input, 3A, 0.45-5.5Vdc Output
is set at 1.1035V and that of the
POWER_GOOD_OFF is set at 1.08V. The values
associated with these commands can be stored in
non-volatile
memory
using
the
STORE_DEFAULT_ALL command.
The PGOOD terminal can be connected through a
pullup resistor (suggested value 100K) to a source
of 5VDC or lower.
Measurement of Output Current, Output
Voltage and Input Voltage
The module is capable of measuring key module
parameters such as output current and voltage and
input voltage and providing this information through
the PMBus interface. Roughly every 200us, the
module makes 16 measurements each of output
current, voltage and input voltage. Average values of
of these 16 measurements are then calculated and
placed in the appropriate registers. The values in the
registers can then be read using the PMBus
interface.
Measuring Output Current Using the PMBus
The module measures current by using the inductor
winding resistance as a current sense element. The
inductor winding resistance is then the current gain
factor used to scale the measured voltage into a
current reading. This gain factor is the argument of
the IOUT_CAL_GAIN command, and consists of two
bytes in the linear data format. The exponent uses
the upper five bits [7:3] of the high data byte in two-s
complement format and is fixed at –15 (decimal). The
remaining 11 bits in two’s complement binary format
represent the mantissa.
The current measurement accuracy is also improved
by each module being calibrated during manufacture
with the offset in the current reading. The
IOUT_CAL_OFFSET command is used to store and
read the current offset. The argument for this
command consists of two bytes composed of a 5-bit
exponent (fixed at -4d) and a 11-bit mantissa. This
command has a resolution of 62.5mA and a range of
-4000mA to +3937.5mA. During manufacture, each
module is calibrated by measuring and storing the
current gain factor and offset into non-volatile
storage.
The READ_IOUT command provides module
average output current information. This command
only supports positive or current sourced from the
module. If the converter is sinking current a reading
of 0 is provided. The READ_IOUT command returns
two bytes of data in the linear data format. The
exponent uses the upper five bits [7:3] of the high
Preliminary Data Sheet
data byte in two-s complement format and is fixed at
–4 (decimal). The remaining 11 bits in two’s
complement binary format represent the mantissa
with the 11^th bit fixed at 0 since only positive numbers
are considered valid.
Note that the current reading provided by the module
is not corrected for temperature. The temperature
corrected current reading for module temperature
T_Module can be estimated using the following equation
IOUT , CORR

1
I_{READ _ OUT}
[(T_IND  30)  0.00393]
where I_{OUT_CORR} is the temperature corrected value of
the current measurement, I_{READ_OUT} is the module
current measurement value, T_IND is the temperature
of the inductor winding on the module. Since it may
be difficult to measure T_IND, it may be approximated
by an estimate of the module temperature.
Measuring Output Voltage Using the PMBus
The module can provide output voltage information
using the READ_VOUT command. The command
returns two bytes of data all representing the
mantissa while the exponent is fixed at -10 (decimal).
During manufacture of the module, offset and gain
correction values are written into the non-volatile
memory of the module. The command
VOUT_CAL_OFFSET can be used to read and/or
write the offset (two bytes consisting of a 16-bit
mantissa in two’s complement format) while the
exponent is always fixed at -10 (decimal). The
allowed range for this offset correction is -125 to
124mV. The command VOUT_CAL_GAIN can be
used to read and/or write the gain correction - two
bytes consisting of a five-bit exponent (fixed at -8)
and a 11-bit mantissa. The range of this correction
factor is -0.125V to +0.121V, with a resolution of
0.004V. The corrected output voltage reading is then
given by:
V_OUT (Final) 
[V_OUT (Initial)  (1 VOUT _ CAL_GAIN)]
 VOUT _CAL_OFFSET
Measuring Input Voltage Using the PMBus
The module can provide output voltage information
using the READ_VIN command. The command
returns two bytes of data in the linear format. The
upper five bits [7:3] of the high data form the two’s
complement representation of the mantissa which is
fixed at –5 (decimal). The remaining 11 bits are used
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Ver 1.6 May. 8, 2013