MW010-Series Power Modules: Data Sheet
36 Vdc to 75 Vdc Inputs; 10 W September 1997
1212 Tyco Electronics Corp.
Feature Descriptions
Output Overvoltage Clamp
The output overvoltage clamp consists of control cir-
cuitry, independent of the primary regulation loop, that
monitors the voltage on the output terminals. The con-
trol loop of the clamp has a set point that is higher than
the set point of the primary loop (see Feature Specifi-
cations table). This provides a redundant voltage-con-
trol that reduces the risk of output overvoltage.
Current Limit
To provide protection in a fault (output overload) condi-
tion, the unit is equipped with internal current-limiting
and can endure current limiting for an unlimited dura-
tion. At the point of current-limit inception, the unit
shifts from voltage control to current control. If the out-
put voltage is pulled very low during a severe fault, the
current-limit circuit can exhibit either foldback or tailout
characteristics (output-current decrease or increase).
The unit operates normally once the output current is
brought back into its specified range.
Optional Remote On/Off
The remote on/off option can be ordered using a code
suffix of “1” (see Ordering Information section). To turn
the power module on and off, the user must supply a
switch to control the voltage between the on/off termi-
nal and the VI(–) terminal (V on/off). The s witch can be an
open collector or equivalent (see Figure 3). A logic low
is V on/off = 0 V to 1.2 V, during which the module is on.
The maximum Ion/off during a logic low is 1 mA. The
s witch should maintain a logic low v oltage while sinking
1 mA.
During a logic high, the maximum Von/off generated by
the power module is 18 V. The maximum allowable
leakage current of the switch at Von/off = 18 V is 50 µA.
Note: A PWB trace between the on/off terminal and
the VI(–) terminal can be used to override the
remote on/off.
CAUTION: To avoid damaging the module or
external circuitry, the VI(–) pin must be
connected to the –48 V source before
or simultaneously to connecting the
on/off pin to the –48 V source (either
directly or through the external on/off
circuitry).
Either the user-supplied switch or the override jumper
should be wired into the circuit via individual traces not
common with the VI(–) po wer current path. Connect the
switch or jumper at the power module terminals (see
Figure 23). Configuring the switch connection in this
way prevents noise from falsely triggering the remote
on/off.
Top view
8-598(C)
Figure 23. Remote On/Off Wiring Configuration
VI(+) VI(–) COMMON
CONNECTION
POINT
V
on/off
+
–
I
on/off
IN
–
+
ON/OFF