GE Industrial Solutions ESTW004A2C Series - Manual (Page 8)

Data Sheet
August 30, 2011
ESTW004A2C Series DC-DC Converter Power Modules
36–75V
dc
Input; 15.0V
dc
/4.2A
dc
Output
LINEAGE POWER 8
Feature Descriptions (continued)
If the unit is configured with the auto-restart option (4),
it will remain in the hiccup mode as long as the
overcurrent condition exists; it operates normally,
once the output current is brought back into its
specified range. The average output current during
hiccup is 10% I
O, max
.
Output Voltage Programming
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.
V
O
(+)
V
O
TRIM
V
O
(-)
R
trim-down
LOAD
V
IN
(+)
ON/OFF
V
IN
(-)
R
trim-up
Figure 11. Circuit Configuration to Trim Output
Voltage.
Connecting an external resistor (R
trim-down
) between
the TRIM pin and the V
O
(-) (or Sense(-)) pin
decreases the output voltage set point. To maintain
set point accuracy, the trim resistor tolerance should
be ±1.0%.
The following equation determines the required
external resistor value to obtain a percentage output
voltage change of Δ%








 22 . 10
%
511
down trim
R
Where
100 %
,
, 







 
 
set o
desired set o
V
V V
For example, to trim-down the output voltage of the
module by 8% to 13.8V, Rtrim-down is calculated as
follows:
8 %
 





 

22 . 10
8
511
down trim
R
 
 655 . 53
down trim
R
Connecting an external resistor (R
trim-up
) between the
TRIM pin and the V
O
(+) (or Sense (+)) pin increases
the output voltage set point. The following equation
determines the required external resistor value to
obtain a percentage output voltage change of Δ%:










 
   


22 . 10
%
511
% 225 . 1
%) 100 ( 11 . 5
, set o
up trim
V
R
Where
100 %
,
, 







 
 
set o
set o desired
V
V V
For example, to trim-up the output voltage of the
module by 5% to 15.75V, R
trim-up
is calculated is as
follows:
5 %
 





 

  


22 . 10
5
511
5 225 . 1
) 5 100 ( 0 . 15 11 . 5
up trim
R
 

M R
up trim
20 . 1
The voltage between the V
O
(+) and V
O
(–) terminals
must not exceed the minimum output overvoltage
protection value shown in the Feature Specifications
table. This limit includes any increase in voltage due
to remote-sense compensation and output voltage
set-point adjustment trim.
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 = V
O,set
x I
O,max
).
Thermal Considerations
The power modules operate in a variety of thermal
environments; however, sufficient cooling should be
provided to help ensure reliable operation.
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.
The thermal reference point, T
ref1
, used in the
specifications for open frame modules is shown in
Figure 12. For reliable operation this temperature
should not exceed 130
o C.
Figure 12. T
ref
Temperature Measurement
Location for Open Frame Module.
AIRFLOW