Data Sheet
EUE Series DC-DC Power Modules:
March 19, 2009
42-55/42-58Vdc Input; 12Vdc Output; 200/120W
Overtemperature Protection
Feature Description
These modules feature an overtemperature protection
circuit to safeguard against thermal damage. The
protection circuit shuts down the module when the
maximum device reference temperature is exceeded.
When the module cools down and the reference
device temperature falls below the recovery threshold,
the module will resume operation.
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 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. Negative
logic, device code suffix "1," is the factory-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 Figure 20). A logic low is Von/off = 0
V to 0.8 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 5 V. The
maximum allowable leakage current of the switch at
Von/off = 5V is 50 µA. If not using the remote on/off
feature, perform one of the following to turn the unit
on:
Input/Output Over Voltage Protection
The input/output overvoltage protection circuit is
designed to shut down the module when the input
voltage exceeds the overvoltage threshold. The
module will resume operation when the input voltage
enters the normal input operating range.
Thermal Considerations
The power modules operate in a variety of thermal
environments and sufficient cooling should be
provided to help ensure reliable operation.
For negative logic, short ON/OFF pin to VI(-).
For positive logic: leave ON/OFF pin open.
Thermal considerations include ambient temperature,
airflow, module power dissipation, and the need for
increased reliability. A reduction in the operating
temperature of the module will result in an increase in
reliability. The thermal data presented here is based
on physical measurements taken in a wind tunnel.
I
on/off
ON/OFF
+
Von/off
–
V
O
(+)
Heat-dissipating components are mounted on the top
side of the module. Heat is removed by conduction,
convection and radiation to the surrounding
environment. Proper cooling can be verified by
measuring the thermal reference temperature (Tref ).
Peak temperature (Tref ) occurs at the position
indicated in Figure 21. For reliable operation this
temperature should not exceed listed temperature
threshold.
LOAD
VO
(–)
V
I
(+)
VI
(–)
Figure 20. Circuit configuration for using Remote
On/Off Implementation.
Overcurrent Protection
To provide protection in an output overload condition,
the module is equipped with internal current-limiting
circuitry and can endure current limiting for unlimited
duration. If the output current exceeds the current limit
inception value, the module enters into the hiccup
mode operation, where it shuts down and
automatically attempts to restart. As long as the fault
condition exists, the module will remain in this hiccup
mode, and can sustain this mode of operation until
the overcurrent fault condition is corrected.
14.50
(.571)
17.45
(.687)
EUE120: SO-8 drain pin must not exceed 115ºC.
EUE200: LF-PAK drain tab must not exceed 120ºC.
Figure 21. Tref Temperature Measurement
Location for Vo=12V.
The output power of the module should not exceed
the rated power for the module as listed in the
Ordering Information table.
Input Undervoltage Lockout
At input voltage below the input under voltage lockout
limit, the module operation is disabled. The module
will begin to operate at an input voltage above the
under voltage lockout turn-on/turn-off threshold.
Although the maximum Tref temperature of the power
modules is 115°C for EUE120 and 120ºC for
LINEAGE POWER
10
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
