GE Industrial Solutions 9-36V ProLynx 3A - Manual (Page 14)

GE Data Sheet
9-36V ProLynx TM 3A: Non-Isolated DC-DC Power Modules
9Vdc –36Vdc input; 3Vdc to 18Vdc output; 3A to 1.5A Scaled output current
9Vdc –24Vdc input; -3.3Vdc to -12Vdc output; 3A to 0.7A Scaled output current
July 23, 2013 ©2013 General Electric Company. All rights reserved. Page 14
Tunable Loop TM
The 9-36V ProLynx TM modules have a new feature that
optimizes transient response of the module called Tunable
Loop
TM .
External capacitors are usually added to the output of the
module for two reasons: to reduce output ripple and noise (see
Figures 30 and 31) and to reduce output voltage deviations
from the steady-state value in the presence of dynamic load
current changes. 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.
The Tunable Loop TM allows the user to externally adjust the
voltage control loop to match the filter network connected to
the output of the module. The Tunable Loop
TM is implemented
by connecting a series R-C between the SENSE and TRIM pins
of the module, as shown in Fig. 38. This R-C allows the user to
externally adjust the voltage loop feedback compensation of
the module.
Recommended values of R
TUNE
and C
TUNE
for different output
capacitor combinations are given in Tables 2, 3 and 4. Tables 2
and 3 show recommended values of R
TUNE
and C
TUNE
for
different values of ceramic output capacitors up to 100 μF that
might be needed for an application to meet output ripple and
noise requirements. Selecting R
TUNE
and C
TUNE
according to
Tables 2 and 3 will ensure stable operation of the module
In applications with tight output voltage limits in the presence
of dynamic current loading, additional output capacitance will
be required. Table 4 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 50% of full
load step change with an input voltage of 12 or 28V.
Figure. 38. Circuit diagram showing connection of R
TUME
and
C
TUNE
to tune the control loop of the module.
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 or input voltages other than
12V/28V.
Table 2. General recommended values of of R
TUNE
and C
TUNE
for Vin=12V and various external ceramic capacitor
combinations.
Vo=5V
Co 1x10 μF 1x22 μF 2x22 μF 4x22 μF 6x22 μF
R
TUNE
330 270 220 180 180
C
TUNE
330pF 680pF 1500pF 2700pF 3300pF
Table 3. General recommended values of of R
TUNE
and C
TUNE
for Vin=28V and various external ceramic capacitor
combinations.
Vo=5V
Co 1x10 μF 1x22 μF 2x22 μF 4x22 μF 6x22 μF
R
TUNE
Open 330 270 220 180
C
TUNE
Open 150pF 470pF 1000pF 1500p
Vo=12V
Co 1x10 μF 1x22 μF 2x22 μF 4x22 μF 6x22 μF
R
TUNE
Open 330 270 270 220
C
TUNE
Open 220p 330p 680p 1200p
Table 4. Recommended values of R
TUNE
and C
TUNE
to obtain
transient deviation of 2% of Vout for a 50% of full load step
Vin 12V 28V
Vo 3.3V 5V 3.3V 5V 12V 18V
∆I 1.5A 1.25A 1.5A 1.25A 1A 0.75A
Co 1x330μF
OsCon
1x330 μF
OsCon
1x330 μF
OsCon
1x330 μF
OsCon 2x22μF 1x22μF
R
TUNE
220 220 270 270 330 Open
C
TUNE
15nF 15nF 5600pF 5600pF 47pF Open
ΔV 26mV 22mV 24mV 20mV 223mV 193mV
MODULE
VOUT
SENSE
TRIM
GND
RTUNE
CTUNE
RTrim
C O