10 Lineage Power
MH005-Series Power Modules: Data Sheet
4.5 Vdc to 14 Vdc Input; 5 W April 2008
Test Configurations (continued)
8-753(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 18. Dual-Output Voltage and Efficiency
Measurement Test Setup
Input Source Impedance
The power module should be connected to a low ac-
impedance input source. Source impedances greater
than 4 µH can affect the stability of the power module.
A 33 µF electrolytic capacitor (ESR < 0.7 ¾ at 100 kHz)
mounted close to the power module helps ensure sta-
bility of the unit.
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).
For the converter output to be considered meeting the
requirements of safety extra-low voltage (SELV), the
input must meet SELV requirements.
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.
V I(+)
I
I
IO
SUPPLY
CONTACT
RESISTANCE
CONTACT AND
DISTRIBUTION LOSSES
LOAD
VI(-)
V
O1
VO2
COM
LOAD
η
VOj(+) VCOM–[] IOj
j1=
∑
VI(+) VI(–)–[] II
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100×= %
