JC050A1 Datasheet, PDF (9/16 Pages) Lineage Power Corporation – Small size: 61.0 mm x 57.9 mm x 12.7 mm (2.40 in. x 2.28 in. x 0.50 in.)

Data Sheet
March 2008
JC050A, JC075A, JC100A Power Modules: dc-dc Converters;
18 Vdc to 36 Vdc Input, 5 Vdc Output; 50 W to 100 W
Design Considerations
Input Source Impedance
Feature Descriptions
Remote On/Off
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 14, 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.
Safety Considerations
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-1950, CSA 22.2-950, and EN60950.
For the converter output to be considered meeting the
requirements of safety extra-low voltage (SELV), the
input must meet SELV requirements.
If the input meets extra-low voltage (ELV) require-
ments, then the converter’s output is considered ELV.
The input to these units is to be provided with a maxi-
mum 20 A normal-blow fuse in the ungrounded lead.
Electrical Descriptions
Current Limit
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
coutput voltage is pulled very low during a severe fault,
the current-limit circuit can exhibit either foldback or tai-
lout characteristics (output current decrease or
increase). The unit operates normally once the output
current is brought back into its specified range.
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 (code suffix “1”) is the factory-preferred configura-
tion.
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 17).
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.
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.
If not using the remote on/off feature, do one of the fol-
lowing:
n For negative logic, short ON/OFF pin to VI(-)
n For positive logic, leave ON/OFF pin open.
Ion/off
+
Von/off
–
ON/OFF
VI(+)
VI(–)
SENSE(+)
VO(+)
VO(–)
SENSE(–)
LOAD
8-720 (C).c
Figure 17. 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(–)] ≤ 0.5 V
Lineage Power
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