GE Industrial Solutions 40A Analog MegaDLynx - Manual (Page 10)

GE
Data Sheet
40A Analog MegaDLynx TM : Non-Isolated DC-DC Power Modules
4.5Vdc –14.4Vdc input; 0.6Vdc to 2.0Vdc output; 40A Output Current
April 24, 2013 ©2012 General Electric Company. All rights reserved. Page 10
Analog Feature Descriptions
Remote On/Off
The 40A Analog MegaDLynx TM power modules feature an
On/Off pin for remote On/Off operation. Two On/Off logic
options are available. In the Positive Logic On/Off option,
(device code suffix “4” – see Ordering Information), the
module turns ON during a logic High on the On/Off pin and
turns OFF during a logic Low. With the Negative Logic On/Off
option, (no device code suffix, see Ordering Information), the
module turns OFF during logic High and ON during logic Low.
The On/Off signal should be always referenced to ground. For
either On/Off logic option, leaving the On/Off pin
disconnected will turn the module ON when input voltage is
present.
For positive logic modules, the circuit configuration for using
the On/Off pin is shown in Figure 21.
For negative logic On/Off modules, the circuit configuration is
shown in Fig. 22..
Figure 21. Circuit configuration for using positive On/Off
logic.
Figure 22. Circuit configuration for using negative On/Off
logic.
Monotonic Start-up and Shutdown
The module has monotonic start-up and shutdown behavior
for any combination of rated input voltage, output current
and operating temperature range.
Startup into Pre-biased Output
The module can start into a prebiased output as long as the
prebias voltage is 0.5V less than the set output voltage.
Analog Output Voltage Programming
The output voltage of the module is programmable to any
voltage from 0.6dc to 2.0Vdc by connecting a resistor
between the Trim and SIG_GND pins of the module. Certain
restrictions apply on the output voltage set point depending
on the input voltage. These are shown in the Output Voltage
vs. Input Voltage Set Point Area plot in Fig. 23. The Upper
Limit curve shows that for output voltages lower than 0.8V,
the input voltage must be lower than the maximum of
14.4V. The Lower Limit curve shows that for output voltages
higher than 0.6V, the input voltage needs to be larger than
the minimum of 4.5V.
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:
MODULE
Internal
Pullup
ON/OFF
I
10K
PWM Enable
470
ON/OFF
Q1
GND
VIN+
ON/OFF
10K
Rpullup
CR1
+
_
V
PWM Enable
VIN+
Internal
Pullup
22K
_
ON/OFF
V
Rpullup
ON/OFF
MODULE
Q1
+
Q3
10K
I
470
GND
10K
22K
ON/OFF