Page 3 of 6 Rev 1
February 3, 2020
DRB-480 Handbook
DDA Series Instruction Manual
3. Terminal Connecting Method
Pay attention to the input wiring, if connected incorrectly, the power supply may be damaged.
Input must be off when making connections.
The output load line and input line shall be separated and twisted to improve noise sensitivity.
When connecting or removing input and output wires, do not apply stress to the PCB.
4. Explanation of Functions and Precautions
(Refer to Full Product Specification for Complete Details)
4-1. Environmental Specifications
DESCRIPTION
OPERATION
STORAGE
Use
Indoor
-
Temperature
-40°C - +100°C
See output derating section
-55°C - +105°C
Humidity
20 - 95% RH, non-condensing
Altitude
2000m
Material Group
Not applicable
Pollution Degree
2
Class
Not applicable
4-2. Input Voltage and Output Ratings
PART NUMBER
INPUT
VOLTAGE
OUTPUT VOLTAGE 1
OUTPUT VOLTAGE 2
MAXIMUM
OUTPUT
CURRENT
MAXIMUM
OUTPUT
POWER
Nominal
Adjust Range
Nominal
Adjust Range
DDA250N-S1PX-12-001
9 – 53V
12V
3.3 to 15V
NA
NA
20A / NA
250W / NA
DDA500N-D2PP-1205-001
9 – 53V
12V
3.3 to 15V
5V
3.3 to 15V
20A / 20A
250W / 250W
DDA325N-D2PN-1212-001
9 – 40V
12V
3.3 to 24V
-12V
-3.3 to -24V
14A / 8A
250W / 75W
Consult factory for other output voltage combinations.
4-3. Output Voltage Adjustment
The output voltage is preset to the nominal value shown on the table above The output can be adjusted within the
specified range through the trim potentiometers on the front panel of the DDA supply (e.g. Vo1 ADJ and Vo2 ADJ).
Turning the potentiometers clockwise increases the output voltage. Due to the wide output adjustment range, care
should be taken to avoid setting the output to a high value that could damage the load. The maximum power
available from the power supply is fixed. As the output voltage is trimmed up, the maximum output current must be
decreased to operate within the maximum rating of the module. Refer to the Output Derating section. As this is a
non-isolated step down converter, the outputs cannot be adjusted higher than the input voltage.
4-4. Remote On/Off
The DDA power supply is equipped with negative logic Remote On/Off feature for each DC output rail located on
terminals 5 (for Vo2) and 6 (for Vo1) of the front panel. Connecting these terminals to Ground [e.g. connect to either
Vo2(-); Vo1(-) terminals] will Enable / Turn On the Outputs. Disconnecting these terminals from Ground (leave open)
will Disable / Turn-Off the Outputs.
When using the Remote On/Off feature on the dual polarity, inverting and non-inverting model such as DDA325N-
D2PN-1212-001, the On/Off terminals should not be connected directly together or the positive output will remain in
an always On condition. Either independent switches should be provided or a low V
F
diode can be installed. Refer to
Full Product Specification for additional details.
4.5 Remote Sense
The Remote Sense feature available on each output rail can be used to compensate for cable distribution drops.
These pin terminals (Pins 1 and 2 on Top Side header connector) should be terminated at the system load
connection for remote sensing. It can compensate up to 5% of output drop which is treated as the maximum potential
permitted between the Output and Sense terminals on the power supply. When using Remote Sense in conjunction
with the Output Adjustment feature, care should be taken not to exceed the maximum compensation limit and/or the
maximum output voltage adjust limit as these are not additive. In both cases, the maximum power should always be
observed. Refer to the Output Derating section.
