HBC48T25120 Datasheet, PDF (6/16 Pages) Power-One – HBC48T25120 DC-DC Converter Data Sheet

HBC48T25120 DC-DC Converter Data Sheet
36-75 VDC Input; 12 VDC @ 25 A Output
Protection Features
Input Undervoltage Lockout (UVLO)
Input undervoltage lockout is standard with this
converter. The converter will shut down when the
input voltage drops below a pre-determined voltage.
The input voltage must be typically 34 V for the
converter to turn on. Once the converter has been
turned on, it will shut off when the input voltage
drops typically below 32 V. This feature is beneficial
in preventing deep discharging of batteries used in
telecom applications.
Output Overcurrent Protection (OCP)
The converter is protected against overcurrent or
short circuit conditions. Upon sensing an overcurrent
condition, the converter will switch to constant
current operation and thereby begin to reduce output
voltage. When the output voltage drops below 60%
of the nominal value of output voltage, the converter
will shut down.
Once the converter has shut down, it will attempt to
restart nominally every 200 ms with a typical 3-5%
duty cycle. The attempted restart will continue
indefinitely until the overload or short circuit
conditions are removed or the output voltage rises
above 60% of its nominal value.
Once the output current is brought back into its
specified range, the converter automatically exits the
hiccup mode and continues normal operation.
Output Overvoltage Protection (OVP)
The converter will shut down if the output voltage
across Vout(+) (Pin 9) and Vout(-) (Pin 5) exceeds
the threshold of the OVP circuitry. The OVP circuitry
contains its own reference voltage, independent of
the output voltage regulation loop. Once the
converter has shut down, it will latch off. The latch
can be reset by toggling the enable pin OFF then ON
or by recycling the input voltage.
Overtemperature Protection (OTP)
The converter will shut down under an
overtemperature condition to protect itself from
overheating caused by operation outside the thermal
derating curves, or operation in abnormal conditions
such as system fan failure. After the converter has
cooled to a safe operating temperature, it will
automatically restart.
Safety Requirements
The converters meet North American and
International safety regulatory requirements per
UL60950-1 and EN60950-1. Basic Insulation is
provided between input and output.
To comply with safety agencies’ requirements, an
input line fuse must be used external to the
converter. A 15 Amp fuse is recommended for use
with this product.
The HBC48T25120 converter is UL approved for a
maximum fuse rating of 15 Amps. To protect a group
of converters with a single fuse, the rating can be
increased from the recommended value above.
MCD10127 Rev. 1.1, 09-Jun-10
Page 6 of 16
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