GE Industrial Solutions Naos Raptor 50A - Manual (Page 11)

Data Sheet
October 31, 2011 Naos Raptor 50A: Non Isolated Power Module:
5 – 14Vdc input; 0.6Vdc to 2.0Vdc Output; 50A output current
LINEAGE POWER 11
Power Good
The Naos Raptor 50A power modules provide a
Power Good Status signal that indicates whether or
not the power module is functioning properly.
PwGood is a power good signal implemented with an
open-collector output to indicate that the output
voltage is within the regulation limits of the power
module. The PwGood signal will be de-asserted to a
low state If any condition such as over-current, or
over-voltage occurs which would result in the output
voltage going out of range.
Monotonic Start-up and Shutdown
The Naos Raptor 50A modules have monotonic start-
up and shutdown behavior for any combination of
rated input voltage, output current and operating
temperature range.
Tunable Loop
The Naos Raptor 50A modules have a new feature
that optimizes transient response of the module called
Tunable Loop. External capacitors are usually added
to improve output voltage transient response due to
load current changes. Sensitive loads may also
require additional output capacitance to reduce output
ripple and noise. Adding external capacitance
however affects the voltage control loop of the
module, typically causing the loop to slow down with
sluggish response. Larger values of external
capacitance could also cause the module to become
unstable.
To use the additional external capacitors in an optimal
manner, the Tunable Loop feature allows the loop to
be tuned externally by connecting a series R-C
between the SENSE and TRIM pins of the module, as
shown in Fig. 25. This R-C allows the user to
externally adjust the voltage loop feedback
compensation of the module to match the filter
network connected to the output of the module.
Recommended values of R
TUNE
and C
TUNE
are given
in Tables 2 and 3. Table 2 lists recommended values
of R
TUNE
and C
TUNE
in order to meet 2% output
voltage deviation limits for some common output
voltages in the presence of a 25A to 50A step change
(50% of full load), with an input voltage of 12V. Table
3 shows the recommended values of R
TUNE
and C
TUNE
for different values of ceramic output capacitors up to
1000uF, again for an input voltage of 12V. The value
of R
TUNE
should never be lower than the values shown
in Tables 2 and 3. Please contact your Lineage Power
technical representative to obtain more details of this
feature as well as for guidelines on how to select the
right value of external R-C to tune the module for best
transient performance and stable operation for other
output capacitance values.
SENSE+
MODULE
TRIM+
VOUT
RTune
TRIM-
CTune
RTrim
Figure. 25. Circuit diagram showing connection of
R
TUME
and C
TUNE
to tune the control loop of the
module.
Table 2. Recommended values of R
TUNE
and C
TUNE
to obtain transient deviation of 2% of Vout for a
25A step load with Vin=12V.
Table 3. General recommended values of of R
TUNE
and C
TUNE
for Vin=12V and various external
ceramic capacitor combinations.
Cext 2x47 μF 4x47μF 10x47μF 20x47μF 40x47μF
R
TUNE
75 75 47 39 33
C
TUNE
1000pF 2200pF 5600pF 10nF 22nF
Vout 1.8V 1.2V 0.6V
Cext
4x47 μF
+
7x330uF
Polymer
4x47 μF
+
12x330uF
Polymer
4x47 μF
+
25x330uF
Polymer
R
TUNE
47 39 33
C
TUNE
33nF 100nF 220nF
ΔV 35mV 23mV 12mV