GE Industrial Solutions EQW012-020-023-025 Series - Manual (Page 13)

Data Sheet
October 5, 2013
EQW012/020/023/025 Series, Eighth-Brick Power Modules:
36 - 75Vdc Input; 1.2Vdc to 5Vdc Output; 12A to 25A Output
LINEAGE POWER 13
Feature Description
Remote On/Off
Two remote on/off options are available. Positive logic
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, device code suffix “1”, turns the
module off during a logic high and on during a logic
low.
To turn the power module on and off, the user must
supply a switch (open collector or equivalent) to
control the voltage (V
on/off
) between the ON/OFF
terminal and the V
IN
(-) terminal (Figure 40). Logic low
is –0.7V ≤ V
on/off
≤ 1.2V. The maximum I
on/off
during
a logic low is 1mA, the switch should be maintain a
logic low level while sinking this current.
During a logic high, the typical V
on/off
generated by the
module is 15V, and the maximum allowable leakage
current at V
on/off
= 15V is 10μA.
If not using the remote on/off feature:
For positive logic, leave the ON/OFF pin open.
For negative logic, short the ON/OFF pin to V
IN
(-).
ON/OFF
V IN (+)
V IN (-)
I on/off
V
on/off
V
O
COM
Figure 40. Circuit configuration for using Remote
On/Off Implementation.
Remote Sense
Remote sense minimizes the effects of distribution
losses by regulating the voltage at the remote-sense
connections (See Figure 41). The voltage between
the remote-sense pins and the output terminals must
not exceed the output voltage sense range given in
the Feature Specifications table:
[VO(+) – VO(–)] – [SENSE(+) – SENSE(–)]
 0.5 V
Although the output voltage can be increased by both
the remote sense and by the trim, the maximum
increase for the output voltage is not the sum of both.
The maximum increase is the larger of either the
remote sense or the trim.
The amount of power delivered by the module is
defined as the voltage at the output terminals
multiplied by the output current. When using remote
sense and trim, the output voltage of the module can
be increased, which at the same output current would
increase the power output of the module. Care should
be taken to ensure that the maximum output power of
the module remains at or below the maximum rated
power (Maximum rated power = Vo,set x Io,max).
V O (+)
SENSE(+)
SENSE(–)
V O (–)
V I (+)
V I (-)
I O LOAD
CONTACT AND
DISTRIBUTION LOSSES
SUPPLY
I I
CONTACT
RESISTANCE
Figure 41. Effective Circuit Configuration for
remote sense operation.
Output Voltage Set-Point Adjustment (Trim)
Trimming allows the output voltage set point to be
increased or decreased, this is accomplished by
connecting an external resistor between the TRIM pin
and either the V
O
(+) pin or the V
O
(-) pin (COM pin) .
V
O
(+)
V
O
TRIM
V
O
(-)
R
trim-down
LOAD
V
IN
(+)
ON/OFF
V
IN
(-)
R
trim-up
Figure 42. Circuit Configuration to Trim Output
Voltage.
Connecting an external resistor (R
trim-down
) between
the TRIM pin and the Vo(-) (or Sense(-)) pin
decreases the output voltage set point. To maintain
set point accuracy, the trim resistor tolerance should
be ±0.1%.
The following equation determines the required
external resistor value to obtain a percentage output
voltage change of ∆%