GE
Data Sheet
QPW025A0F41/QPW025A0F41-H DC-DC Power Module
36-75Vdc Input; 3.3Vdc Output Voltage; 25A Output Current
October 5, 2015 ©2012 General Electric Company. All rights reserved. Page 7
One pole of the input and one pole of the output
are to be grounded, or both circuits are to be kept
floating, to maintain the output voltage to ground
voltage within ELV or SELV limits
.
For all input sources, other than DC MAINS, where the
input voltage is between 60 and 75V dc (Classified as
TNV-2 in Europe), the following must be meet, if the
converter’s output is to be evaluated for SELV:
The input source is to be provided with reinforced
insulation from any hazardous voltage, including
the ac mains.
One Vi pin and one Vo pin are to be reliably
earthed, or both the input and output pins are to
be kept floating.
Another SELV reliability test is conducted on the
whole system, as required by the safety agencies,
on the combination of supply source and the
subject module to verify that under a single fault,
hazardous voltages do not appear at the module’s
output.
The power module has ELV (extra-low voltage) outputs
when all inputs are ELV.
All flammable materials used in the manufacturing of
these modules are rated 94V-0, or tested to the
UL60950 A.2 for reduced thickness.
The input to these units is to be provided with a
maximum 6A fast-acting (or time-delay) fuse in the
unearthed lead.
Feature Descriptions
Remote On/Off
Two remote On/Off logic options are available. Positive
logic remote On/Off turns the module ON during a
logic-high voltage on the remote On/Off pin, and turns
the module OFF during a logic-low. Negative logic
remote On/Off turns the module OFF during a logic-
high and turns the module ON during logic-low.
Negative logic is specified by suffix “1” at the end of the
device code.
To turn the power module on and off, the user must
supply a switch to control the voltage between the
ON/OFF pin and the V
IN
(–) terminal (V
on/Off
). The switch
may be an open collector or equivalent (see Figure 10).
A logic-low is V
on/off
= 0 V to 1.2V. The maximum Ion/off
during a logic low is 1 mA. The switch should maintain
a logic-low voltage while sinking 1 mA.
During a logic-high, the maximum Von/off generated
by the power module is 15 V. The maximum allowable
leakage current of the switch is 50 µA. If not using the
remote on/off feature, do one of the following:
For positive logic, leave the ON/OFF pin open.
For negative logic, short the ON/OFF pin to V
IN
(–).
SENSE(+)
V
O
(+)
SENSE(–)
V
O
(–)
V
I
(-)
+
–
I
on/off
ON/OFF
V
I
(+)
LOA
V
on/off
Figure 10. Circuit configuration for using Remote
On/Off Implementation.
Overcurrent Protection
To provide protection in a fault (output overload) condi-
tion, the module is equipped with internal current-limit-
ing circuitry, and can endure current limiting
continuously. At the instance of current-limit inception,
the output current begins to tail-out. When an
overcurrent condition exists beyond a few seconds, the
module enters a “hiccup” mode of operation, whereby
it shuts down and automatically attempts to restart..
While the fault condition exists, the module will remain
in this hiccup mode, and can remain in this mode until
the fault is cleared. The unit operates normally once
the output current is reduced back into its specified
range.
Input Undervoltage Lockout
At input voltages below the input undervoltage lockout
limit, the module operation is disabled. The module will
begin to operate at an input voltage between the
undervoltage lockout limit and the minimum operating
input voltage.
Overtemperature Protection
To provide over temperature protection in a fault
condition, the unit relies upon the thermal protection
feature of the controller IC. The unit will shut down if
the thermal reference point T
ref
, exceeds the specified
maximum temperature threshold, but the thermal
shutdown is not intended as a guarantee that the unit
will survive temperatures beyond its rating. The
module will automatically restart after it cools down.
