JAW050A and JAW075A Power Modules; dc-dc Converters:
36 Vdc to 75 Vdc Input, 5 Vdc Output; 50 W to 75 W
Data Sheet
April 2008
Design Considerations
Input Source Impedance
Feature Descriptions
Overcurrent Protection
The power module should be connected to a low
ac-impedance input source. Highly inductive source
impedances can affect the stability of the power mod-
ule. For the test configuration in Figure 11, a 33 µF
electrolytic capacitor (ESR < 0.7 Ω at 100 kHz)
mounted close to the power module helps ensure sta-
bility of the unit. For other highly inductive source
impedances, consult the factory for further application
guidelines.
To provide protection in an output overload condition,
the unit is equipped with an internal shutdown and
auto-restart mechanism. At the instance of current-limit
inception, the module enters a hiccup mode of opera-
tion whereby it shuts down and automatically attempts
to restart. As long as the fault persists, the module
remains in this mode.
The protection mechanism is such that the unit can
continue in this condition until the fault is cleared.
Safety Considerations
Remote On/Off
For safety-agency approval of the system in which the
power module is used, the power module must be
installed in compliance with the spacing and separation
requirements of the end-use safety agency standard,
i.e., UL 60950, CSA C22.2 No. 60950-00, and
VDE 0805 (IEC 60950, 4th Edition).
Two remote on/off options are available. Positive logic
remote on/off turns the module on during a logic-high
voltage on the ON/OFF pin, and off during a logic low.
Negative logic remote on/off turns the module off dur-
ing a logic high and on during a logic low. Negative
logic, device code suffix “1,” is the factory-preferred
configuration.
If the input source is non-SELV (ELV or a hazardous
voltage greater than 60 Vdc and less than or equal to
75 Vdc), for the module's output to be considered
meeting the requirements of safety extra-low voltage
(SELV), all of the following must be true:
To turn the power module on and off, the user must
supply a switch to control the voltage between the
on/off terminal and the VI(–) terminal (Von/off). The
switch can be an open collector or equivalent (see
Figure 14). A logic low is Von/off = 0 V to 1.2 V. The
maximum Ion/off during a logic low is 1 mA. The switch
should maintain a logic-low voltage while sinking 1 mA.
n The input source is to be provided with reinforced
insulation from any other hazardous voltages, includ-
ing the ac mains.
During a logic high, the maximum Von/off generated by
the power module is 15 V. The maximum allowable
leakage current of the switch at Von/off = 15 V is 50 µA.
n One VI pin and one VO pin are to be grounded, or
both the input and output pins are to be kept floating.
n The input pins of the module are not operator acces-
If not using the remote on/off feature, do one of the
following:
sible.
n 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.
n For negative logic, short the ON/OFF pin to VI(–).
n For positive logic, leave the ON/OFF pin open.
Note: Do not ground either of the input pins of the
module without grounding one of the output
pins. This may allow a non-SELV voltage to
appear between the output pins and ground.
The power module has extra-low voltage (ELV) outputs
when all inputs are ELV.
The input to these units is to be provided with a maxi-
mum 6 A normal-blow fuse in the ungrounded lead.
8
Lineage Power
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
