UVT020A0X3-SRZ Lineage Power, UVT020A0X3-SRZ Datasheet - Page 22

• Manufacturer Part Number: UVT020A0X3-SRZ
• Description: DC/DC Converters & Regulators 3-14.4Vin .6-5.5Vout 20A Neg SMT Analog
• Manufacturer: Lineage Power

Specifications of UVT020A0X3-SRZ

• Product: Non-Isolated / POL
• Input Voltage Range: 3 VDC to 14.4 VDC
• Input Voltage (nominal): 12 V
• Output Voltage (channel 1): 0.6 VDC to 5.5 VDC
• Output Current (channel 1): 20 A
• Output Voltage: 0.6 VDC to 5.5 VDC
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Preliminary Data Sheet
May 10, 2011
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
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 The
LINEAGE
V
V
OUT
OUT
4.
(
(
PGOOD
PGOOD
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).
POWER
_
_
ON
OFF
)
)
=
=
(
(
POWER
POWER
_
_
GOOD
GOOD
20A Digital Micro DLynx
_
_
ON
OFF
3 – 14.4Vdc input; 0.45Vdc to 5.5Vdc output; 20A output
)
×
)
2
×
−
2
10
−
10
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.
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 200μs, the module
makes 16 measurements each of output current,
voltage and input voltage. Average values of each of
these measurements are then calculated and placed in
the appropriate registers. These 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
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
TM
: Non-isolated DC-DC Power Modules
can be estimated using the following equation
th
bit fixed at
22