LANC1215DW8 Datasheet, PDF (4/14 Pages) Wall Industries,Inc. – DC/DC Converter 9-18 VDC Input ±15 VDC Output at ±0.267A

TECHNICAL DATASHEET
LANC1215DW8
DESIGN CONSIDERATIONS:
Output Over Current Protection
When excessive output currents occur in the system, circuit protection is required on all power supplies.
Normally, overload current is maintained at approximately 150% of rated current for the LANCW8 dual output
series.
Fold back-mode is a method of operation in a power supply whose purpose is to protect the power supply from
being damaged during an over-current fault condition. It also enables the power supply to operate normally when
the fault is removed.
One of the problems resulting from over current is that excessive heat may be generated in power devices;
especially MOSFET and Schottky diodes and the temperature of those devices may exceed their specified limits.
A protection mechanism has to be used to prevent those power devices from being damaged.
The operation of fold back is as follows. When the current sense circuit sees an over-current event, the output
voltage of the module will be decreased for low power dissipation and decrease the heat of the module.
Figure 2
Input Source Impedance
The power module should be connected to a low impedance input source. Highly inductive source impedance
can affect the stability of the power module. Input external L-C filter is recommended to minimize input
reflected ripple current. The inductor is simulated source impedance of 12µH and capacitor is Nippon chemi-con
KZE series 47µF/100V. The capacitor must as close as possible to the input terminals of the power module for
lower impedance.
Thermal Consideration
The power module operates in a variety of thermal environments. However, sufficient cooling should be
provided to help ensure reliable operation of the unit. Heat is removed by conduction, convention, and radiation
to the surrounding environment. Proper cooling can be verified by measuring the point as the figure below. The
temperature at this location should not exceed 105°C. When operating, adequate cooling must be provided to
maintain the test point temperature at or below 105°C. Although the maximum point temperature of the power
modules is 105°C, you can limit this temperature to a lower value for extremely high reliability.
Figure 3
TOP VIEW
Measurement shown in inches and millimeters
(888) 597-WALL
0.625 (15.9)
www.wallindustries.com
Page 4 of 14