GE Industrial Solutions 40A Digital MegaDLynx - Manual (Page 12)

GE
Data Sheet
40A Digital MegaDLynx TM : Non-Isolated DC-DC Power Modules
4.5Vdc –14.4Vdc input; 0.45Vdc to 2.0Vdc output; 40A Output Current
April 24, 2013 ©2012 General Electric Company. All rights reserved. Page 12
Figure 23. Output Voltage vs. Input Voltage Set Point Area
plot showing limits where the output voltage can be set for
different input voltages.
V
O
(+)
TRIM
VS─
R
trim
LOAD
V
IN
(+)
ON/OFF
VS+
SIG_GND
Caution – Do not connect SIG_GND to GND elsewhere in the
layout
Figure 24. Circuit configuration for programming output
voltage using an external resistor.
Without an external resistor between Trim and SIG_GND pins,
the output of the module will be 0.6Vdc.To calculate the value
of the trim resistor, Rtrim for a desired output voltage, should
be as per the following equation:
 









k
Vo
Rtrim
6 . 0
12
Rtrim is the external resistor in kΩ
Vo is the desired output voltage.
Table 1 provides Rtrim values required for some common
output voltages.
Table 1
V
O, set
(V) Rtrim (KΩ)
0.6 Open
0.9 40
1.0 30
1.2 20
1.5 13.33
1.8 10
Digital Output Voltage Adjustment
Please see the Digital Feature Descriptions section.
Remote Sense
The power module has a Remote Sense feature to minimize
the effects of distribution losses by regulating the voltage
between the sense pins (VS+ and VS-). The voltage drop
between the sense pins and the VOUT and GND pins of the
module should not exceed 0.5V.
Analog Voltage Margining
Output voltage margining can be implemented in the
module by connecting a resistor, R
margin-up
, from the Trim pin
to the ground pin for margining-up the output voltage and
by connecting a resistor, R
margin-down
, from the Trim pin to
output pin for margining-down. Figure 25 shows the circuit
configuration for output voltage margining. The POL
Programming Tool, available at
www.lineagepower.com
under the Downloads section, also calculates the values of
R
margin-up
and R
margin-down
for a specific output voltage and %
margin. Please consult your local GE technical
representative for additional details.
Figure 25. Circuit Configuration for margining Output
voltage.
Digital Output Voltage Margining
Please see the Digital Feature Descriptions section.
Output Voltage Sequencing
The power module includes a sequencing feature, EZ-
SEQUENCE that enables users to implement various types of
output voltage sequencing in their applications. This is
accomplished via an additional sequencing pin. When not
using the sequencing feature, leave it unconnected.
The voltage applied to the SEQ pin should be scaled down
by the same ratio as used to scale the output voltage down
to the reference voltage of the module. This is accomplished
by an external resistive divider connected across the
sequencing voltage before it is fed to the SEQ pin as shown
in Fig. 26. In addition, a small capacitor (suggested value
100pF) should be connected across the lower resistor R1.
For all DLynx modules, the minimum recommended delay
between the ON/OFF signal and the sequencing signal is
Vo
MODULE
SIG_GND
Trim
Q1
Rtrim
Rmargin-up
Q2
Rmargin-down