FEATURES DESCRIPTIONS
Over-Current Protection
The modules include an internal output over-current
protection circuit, which will endure current limiting for an
unlimited duration during output overload. If the output
current exceeds the OCP set point, the modules will shut
down, and will try to restart after shutdown(hiccup mode).
If the overload condition still exists, the module will shut
down again. This restart trial will continue until the
overload condition is corrected.
Over-Voltage Protection
The modules include an internal output over-voltage
protection circuit, which monitors the voltage on the output
terminals. If this voltage exceeds the over-voltage set
point, the protection circuit will constrain the max duty
cycle to limit the output voltage, if the output voltage
continuously increases the modules will shut down, and
then restart after a hiccup-time (hiccup mode).
Over-Temperature Protection
The over-temperature protection consists of circuitry that
provides protection from thermal damage. If the
temperature exceeds the over-temperature threshold the
module will shut down.The module will restart after the
temperature is within specification.
Remote On/Off
The remote on/off feature on the module can be either
negative or positive logic. Negative logic turns the module
on during a logic low and off during a logic high. Positive
logic turns the modules on during a logic high and off
during a logic low.
Remote on/off can be controlled by an external switch
between the on/off terminal and the Vi (-) terminal. The
switch can be an open collector or open drain. For
negative logic if the remote on/off feature is not used,
please short the on/off pin to Vi (-). For positive logic if the
remote on/off feature is not used, please leave the on/off
pin to floating.
Figure 16: Remote on/off implementation
Basic insulation based on 75 Vdc input is provided
between the input and output of the module for the
purpose of applying insulation requirements when the
input to this DC-to-DC converter is identified as TNV-2 or
SELV. An additional evaluation is needed if the source is
other than TNV-2 or SELV.
When the input source is SELV circuit, the power module
meets SELV (safety extra-low voltage) requirements. If
the input source is a hazardous voltage which is greater
than 60 Vdc and less than or equal to 75 Vdc, for the
module’s output to meet SELV requirements, all of the
following must be met:
The input source must be insulated from the ac
mains by reinforced or double insulation.
The input terminals of the module are not operator
accessible.
A SELV reliability test is conducted on the system
where the module is used, in combination with the
module, to ensure that under a single fault,
hazardous voltage does not appear at the module’s
output.
When installed into a Class II equipment (without
grounding), spacing consideration should be given to
the end-use installation, as the spacing between the
module and mounting surface have not been evaluated.
The power module has extra-low voltage (ELV) outputs
when all inputs are ELV.
This power module is not internally fused. To achieve
optimum safety and system protection, an input line fuse
is highly recommended. The safety agencies require a
normal-blow fuse with 20A maximum rating to be
installed in the ungrounded lead. A lower rated fuse can
be used based on the maximum inrush transient energy
and maximum input current.
Soldering and Cleaning Considerations
Post solder cleaning is usually the final board assembly
process before the board or system undergoes electrical
testing. Inadequate cleaning and/or drying may lower the
reliability of a power module and severely affect the
finished circuit board assembly test. Adequate cleaning
and/or drying is especially important for un-encapsulated
and/or open frame type power modules. For assistance
on appropriate soldering and cleaning procedures,
please contact Delta’s technical support team.