GE Industrial Solutions 12A Analog PicoDLynx - Manual (Page 13)

GE
Data Sheet
12A Analog PicoDLynx TM : Non-Isolated DC-DC Power Modules
3Vdc –14.4Vdc input; 0.6Vdc to 5.5Vdc output; 12A Output Current
August 13, 2013 ©2013 General Electric Corporation. All rights reserved. Page 13
Feature Descriptions
Remote On/Off
The 12A Analog PicoDLynx 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 39. When the external
transistor Q1 is in the OFF state, the internal PWM Enable
signal is pulled high through an internal resistor and the
external pullup resistor and the module is ON. When
transistor Q1 is turned ON, the On/Off pin is pulled low and
the module is OFF. A suggested value for R
pullup
is TBD
TBA
Figure 39. Circuit configuration for using positive On/Off
logic.
For negative logic On/Off modules, the circuit configuration
is shown in Fig. 40. The On/Off pin should be pulled high with
an external pull-up resistor (suggested value for the 3V to
14.4V input range is 20Kohms). When transistor Q1 is in the
OFF state, the On/Off pin is pulled high, internal transistor Q4
is turned ON and the module is OFF. To turn the module ON,
Q1 is turned ON pulling the On/Off pin low, turning transistor
Q4 OFF resulting in the PWM Enable pin going high and the
module turning ON.
Figure 40. 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 modules can start into a prebiased output as long as
the prebias voltage is 0.5V less than the set output voltage.
Output Voltage Programming
The output voltage of the module is programmable to any
voltage from 0.6dc to 5.5Vdc by connecting a resistor
between the Trim and 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. 41. The Upper
Limit curve shows that for output voltages lower than 1V,
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 3V.
Figure 41. 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
R
trim
LOAD
V
IN
(+)
ON/OFF
VS+
GND
Figure 42. Circuit configuration for programming output
voltage using an external resistor.
Without an external resistor between Trim and 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:
PVX012 NEGATIVE LOGIC FIGURE
22K
Q4
Rpullup
I
ON/OFF
GND
VIN+
ON/OFF
22K
PWM Enable
+
_
ON/OFF
V
CSS Q1
MODULE
0
2
4
6
8
10
12
14
16
0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6
Input
V
ol
ta
ge
(
v
)
Output Voltage (V)
Lower
Upper