Data Sheet
QUK240 Series Power Modules; DC-DC converters
36 – 55Vdc input; 9Vdc Output; 240W
June 17, 2009
An auto-restart option is also available. An auto-
restart feature continually attempts to restore the
operation until fault condition is cleared.
Feature Description
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 12). A logic low is Von/off = 0
V to I.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 = 15V is 50 µA. If not using the remote on/off
feature, perform one of the following to turn the unit
on:
Input Undervoltage Lockout
At input voltages above or below the input under/over
voltage lockout limits, module operation is disabled.
The module will begin to operate when the input
voltage level changes to within the under and
overvoltage lockout limits.
Overtemperature Protection
These modules feature an overtemperature protection
circuit to safeguard against thermal damage. The
circuit shuts down and latches off the module when
the maximum device reference temperature is
exceeded. The module can be restarted by cycling
the dc input power for at least one second or by
toggling the remote on/off signal for at least one
second.
For negative logic, short ON/OFF pin to VI(-).
For positive logic: leave ON/OFF pin open.
Input/Output Overvoltage 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.
I
on/off
ON/OFF
+
Von/off
–
V
O
(+)
LOAD
V
O
(–)
VI(+)
VI(–)
Figure 12. Remote On/Off Implementation
Overcurrent Protection
To provide protection in a fault output overload
condition, the module is equipped with internal
current-limiting circuitry and can endure current
limiting for a few mili-seconds. If the overcurrent
condition persists beyond a few milliseconds, the
module will shut down and remain latched off. The
overcurrent latch is reset by either cycling the input
power or by toggling the on/off pin for one second. If
the output overload condition still exists when the
module restarts, it will shut down again. This
operation will continue indefinitely until the
overcurrent condition is corrected.
LINEAGE POWER
8
