PDT006A0X3-SRZ Datasheet, PDF (22/39 Pages) Lineage Power Corporation – 6A Digital Pico DLynxTM: Non-Isolated DC-DC Power Modules 3Vdc ––14.4Vdc input; 0.45Vdc to 5.5Vdc output; 6A Output Current

Preliminary Data Sheet
October 17, 2011
6A Digital Pico DLynx^TM: Non-isolated DC-DC Power Modules
3 –– 14.4Vdc input; 0.45Vdc to 5.5Vdc output; 6A output current
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. If other values are entered for either
command, they will be mapped to the closest of the
allowed values.
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 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 100KΩ) 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 200ȝs, 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. During manufacture, each module is
calibrated by measuring and storing the current gain
factor into non-volatile storage.
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.
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 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 TModule
can be estimated using the following equation
ࡵ_{ࡻࢁࢀǡ࡯ࡻࡾࡾ}
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ࡵ_{ࡾࡱ࡭ࡰ̴ࡻࢁࢀ}
ሾሺࢀ_{ࡵࡺࡰ} െ ૜૙ሻ ൈ
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LINEAGE POWER
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