PDT006A0X3-SRZ Datasheet, PDF (20/39 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
Bit Position
Access
Function
Default Value
4
3
2
1
0
r/w r/w r/w r/w r
PU CMD CPR POL CPA
1
0
1
1
1
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.
Bit Value
0
1
Action
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.
CMD: The CMD bit controls how the device responds to
the OPERATION command.
Bit Value
0
1
Action
Module ignores the ON bit in the
OPERATION command
Module responds to the ON bit in 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.
Bit Value
0
1
Action
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
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 600ʅs 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.
Table 5
Rise Time
600ʅs
900ʅs
1.2ms
1.8ms
2.7ms
4.2ms
6.0ms
9.0ms
Exponent
11100
11100
11100
11100
11100
11100
11100
11100
Mantissa
00000001010
00000001110
00000010011
00000011101
00000101011
00001000011
00001100000
00010010000
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 20kŸ upper divider resistor
inside the module, and the internal reference voltage of
the module. The reference voltage VREF is nominally set
at 600mV, and the output regulation voltage is then
given by
V_OUT
=
ª
«¬
20000 + RTrim
RTrim
º
»¼
×
V_REF
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:
VOUT
_
SCALE _
LOOP
=
RTrim
20000+ RTrim
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 VREF is what is 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
LINEAGE POWER
20