Data Sheet
July 1999
36 Vdc to 75 Vdc Inputs; 30 W
JW030-Series Power Modules:
12 Tyco Electronics Corp.
Feature Descriptions
Overcurrent Protection
To provide protection in a fault (output overload) condi-
tion, the unit is equipped with internal current-limiting
circuitry and can endure current limiting for an unlim-
ited duration. At the point of current-limit inception, the
unit shifts from voltage control to current control. If the
output voltage is pulled very low during a severe fault,
the current-limit circuit can exhibit eit her foldback or
tailout characteristics (output current decrease or
increase). The unit operates normally once the output
current is brought back into its specified range.
Remote On/Off
Two remote on/off options are available. Positive logic
remote on/off turns the module on during a logic-high
voltage on the REMOTE ON/OFF pin, and off during a
logic low . Negative logic remote on/off turns the module
off during a logic high and on during a logic low. Nega-
tive logic, device code suffix “1,” is the f actory-preferred
configuration.
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 Fig-
ure 23). A logic low is Von/off = –0.7 V to 1.2 V, during
which the module is off. The maximum Ion/off dur i ng 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 6 V. The maximum allowable leak-
age current of the switch at Von/off = 6 V is 50 µA.
The module has internal capacitance to reduce noise
at the ON/OFF pin. Additional capacitance is not gen-
erally needed and may degrade the start-up character-
istics of the module.
CA UTION: T o a void damaging the power module or
external on/off circuit, the connection
between the VI(–) pin and the input
sourc e must be made before or simulta-
neously to making a connection
between the ON/OFF pin and the input
source (either directly or through the
external on/off circ uit.)
8-720(C).h
Figure 23. Remote On/Off Implementation
Remote Sense
Remote sense minimizes the effects of distribution
losses by regulating the voltage at the remote-sense
connections. The voltage between the remote-sense
pins and the output terminals must not exceed the out-
put voltage sense range given in the Feature Specifica-
tions table, i.e.:
[VO(+) – VO(–)] – [SENSE(+ ) – SENSE ( –)] ð 0.2 V
The voltage between the VO(+) and VO(–) termi nal s
must not exceed the minimum output overvoltage shut-
down v oltage as indicated in the F eature Specifications
table. This limit includes any increase in voltage due to
remote-sense compensation and output voltage set-
point adjustment (trim). See Figure 24.
If not using the remote-sense feature to regulate the
output at the point of load, then connect SENSE(+) to
VO(+) and SENSE(–) to VO(–) at the module.
8-651(C).m
Figure 24. Effective Circ uit Configuration for
Single-Module Remote-Sense Operat ion
+
Ion/off
–
Von/off
REMOTE
ON/OFF
VI(+)
VI(-) SENSE(+)
SENSE(–)
VO(+)
VO(–)LOAD
VO(+)
SENSE(+)
SENSE(–)
VO(–)
VI(+)
VI(-)
IOLOAD
CONTACT AND
DISTRIBUTION LOSSES
SUPPLY II
CONTACT
RESISTANCE