GE Industrial Solutions 3A Analog PicoDLynx - Manual (Page 13)

GE
Preliminary Data Sheet
3A Analog PicoDLynx TM : Non-Isolated DC-DC Power Modules
3Vdc –14.4Vdc input; 0.6Vdc to 5.5Vdc output; 3A Output Current
December 7, 2012 ©2012 General Electric Company. All rights reserved. Page 13
Feature Descriptions
Remote On/Off
The 3A 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 12V. 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
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
In
p
u
t V
o
lt
ag
e
Output Voltage
Upper Limit
Lower Limit