1414 Lineage Power
Data Sheet
April 2008
39.5 Vdc to 60 Vdc Input; 5 W
ME005-Series Power Modules:
Test Configurations (continued)
8-506(C)
Note:All measurements are taken at the module terminals. When
socketing, place Kelvin connections at module terminals to
avoid measurement errors due to socket contact resistance.
Figure 34. ME005BK, CL Output Voltage and
Efficiency Measurement Test Setup
Design Considerations
Input Reflected Ripple
An internal aluminum electrolytic input capacitor is
used for filtering; therefore, input ripple increases as
temperature decreases. There is approximately two
times more ripple at 0 °C than at 25 °C and eight times
more ripple at –40 °C than at 25 °C. The power module
functions properly down to –40 °C with no additional fil-
tering. If ripple comparable to that at 25 °C is needed at
low temperatures, an external capacitor across the
input with an impedance of 0.5 Ω at 100 kHz over the
desired temperature range is recommended.
Output Voltage Reversal
CAUTION: Applying a reverse voltage across the
module output forward biases an inter-
nal diode. Attempting to start the mod-
ule under this condition can damage
the module.
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 C22.2 No. 950-95, and VDE 0805
(EN60950, IEC950).
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:
n The input source is to be provided with reinforced
insulation from any other hazardous voltages, includ-
ing the ac mains.
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-
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.
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 5 A normal-blow fuse in the ungrounded lead.
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 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.
Output Overvoltage Protection
The output overvoltage clamp consists of control cir-
cuitry, which is independent of the primary regulation
loop, that monitors the voltage on the output terminals.
The control loop of the clamp has a higher voltage set
point than the primary loop (see Feature Specifications
table). This provides a redundant voltage-control that
reduces the risk of output overvoltage.
UPPLY
V
I
(+)
V
I
(-)
V
O1
V
O2
I
I
CONTACT
RESISTANCE
CONTACT AND
DISTRIBUTION LOSSES
LOA
COM
LOA
η
VOj(+) VCOM–[] IOj
j1=
∑
VI(+) VI(–)–[] II
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100×= %
