UDT020A0X3-SRZ Lineage Power, UDT020A0X3-SRZ Datasheet - Page 20

• Manufacturer Part Number: UDT020A0X3-SRZ
• Description: DC/DC Converters & Regulators 3-14.4Vin .6-5.5Vout 20A Neg SMT Digital
• Manufacturer: Lineage Power

Specifications of UDT020A0X3-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
PU: Sets the default to either operate any time input
power is present or for the ON/OFF to be controlled by
the analog ON/OFF input and the PMBus
OPERATION command. This bit is used together with
the CP, CMD and ON bits to determine startup.
CMD: The CMD bit controls how the device responds
to the OPERATION command.
CPR: Sets the response of the analog ON/OFF pin.
This bit is used together with the CMD, PU and ON
bits to determine startup.
PMBus Adjustable Soft Start Rise Time
The soft start rise time can be adjusted in the module
via PMBus. When setting this parameter, make sure
that the charging current for output capacitors can be
delivered by the module in addition to any load current
to avoid nuisance tripping of the overcurrent protection
circuitry during startup. The TON_RISE command sets
the rise time in ms, and allows choosing soft start
times between 600μs and 9ms, with possible values
listed in Table 5. Note that the exponent is fixed at -4
(decimal) and the upper two bits of the mantissa are
also fixed at 0.
LINEAGE
Bit Value
Bit Value
Bit Value
Default Value
Bit Position
Function
0
1
0
1
0
1
Access
POWER
Module powers up any time power is
present regardless of state of the analog
ON/OFF pin
Module does not power up until
commanded by the analog ON/OFF pin
and the OPERATION command as
programmed in bits [2:0] of the
ON_OFF_CONFIG register.
Module ignores the ON bit in the
OPERATION command
Module responds to the ON bit in the
OPERATION command
Module ignores the analog ON/OFF pin,
i.e. ON/OFF is only controlled through the
PMBUS via the OPERATION command
Module requires the analog ON/OFF pin
to be asserted to start the unit
r/w
PU
4
1
CMD CPR
r/w
3
0
Action
Action
Action
20A Digital Micro DLynx
r/w
2
1
POL
r/w
1
1
3 – 14.4Vdc input; 0.45Vdc to 5.5Vdc output; 20A output
CPA
0
1
r
Output Voltage Adjustment Using the PMBus
The VOUT_SCALE_LOOP parameter is important for
a number of PMBus commands related to output
voltage trimming, margining, over/under voltage
protection and the PGOOD thresholds. The output
voltage of the module is set as the combination of the
voltage divider formed by RTrim and a 20kΩ upper
divider resistor inside the module, and the internal
reference voltage of the module. The reference voltage
V
regulation voltage is then given by
Hence the module output voltage is dependent on the
value of RTrim which is connected external to the
module. The information on the output voltage divider
ratio is conveyed to the module through the
VOUT_SCALE_LOOP parameter which is calculated
as follows:
The VOUT_SCALE_LOOP parameter is specified
using the “Linear” format and two bytes. The upper five
bits [7:3] of the high byte are used to set the exponent
which is fixed at –9 (decimal). The remaining three bits
of the high byte [2:0] and the eight bits of the lower
byte are used for the mantissa. The default value of
the mantissa is 00100000000 corresponding to 256
(decimal), corresponding to a divider ratio of 0.5. The
maximum value of the mantissa is 512 corresponding
to a divider ratio of 1. Note that the resolution of the
VOUT_SCALE_LOOP command is 0.2%.
When PMBus commands are used to trim or margin
the output voltage, the value of V
changed inside the module, which in turn changes the
regulated output voltage of the module.
The nominal output voltage of the module can be
adjusted with a minimum step size of 0.4% over a
±25% range from nominal using the VOUT_TRIM
command over the PMBus.
The VOUT_TRIM command is used to apply a fixed
offset voltage to the output voltage command value
REF
TM
: Non-isolated DC-DC Power Modules
VOUT
is nominally set at 600mV, and the output
Rise Time
V
600μs
900μs
1.2ms
1.8ms
2.7ms
4.2ms
6.0ms
9.0ms
OUT
_
SCALE
=



20000
Exponent
11100
11100
11100
11100
11100
11100
11100
11100
_
Table 5
RTrim
LOOP
+
RTrim
=
REF
00000001010
00000001110
00000010011
00000011101
00000101011
00001000011
00001100000
00010010000
20000
Mantissa
is what is



RTrim
×
+
V
RTrim
REF
20