HBA48T12280 Power-One, HBA48T12280 Datasheet - Page 8

• Manufacturer Part Number: HBA48T12280
• Description: Hba48t12280 Dc-dc Converter 36-75 Vdc Input; 28 Vdc @ 12.5 A Output
• Manufacturer: Power-One

limits of trim range previously specified must be
observed.
Note: It is important to note that when using this trimming method
the control voltage, V
after the converter output has stabilized at its nominal output level.
Applying V
discontinuous start-up waveform.
Figure F: Configuration for changing output voltage by using
an external control voltage.
If the user application requires the use of both
resistive and voltage mode trimming, the above
equations would need to be modified; please consult
Power-One Technical Support.
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 35 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 33 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 10%
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 100 ms with a typical 15%
duty cycle. The attempted restart will continue
indefinitely until the overload or short circuit condition
is removed or the output voltage rises above 10% 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.
BCD.00009.1 Rev. AA, 20-Oct-09
V
IN
TRIM
to the trim pin prior to enable may result in a
ON / OFF
VIN (+)
VIN ( - )
CASE
TRIM
( Top View )
, should be applied to the trim pin only
SENSE (+)
SENSE ( - )
VOUT (+)
VOUT ( - )
TRIM
Rload
V
TRIM
HBA48T12280 DC-DC Converter Data Sheet
36-75 VDC Input; 28 VDC @ 12.5 A Output
Page 8 of 14
Output Overvoltage Protection (OVP)
The converter will shut down if the output voltage
across Vout(+) and Vout(-) 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
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
International safety regulatory requirements per
UL60950 and EN60950 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 20-Amp fuse is recommended for use
with this product.
The HBA48T12280 converter is UL approved for a
maximum fuse rating of 20 Amps. To protect a group
of converters with a single fuse, the rating can be
increased from the recommended value above.
Characterization
General Information
The converter has been characterized for many
operational aspects, to include thermal derating
(maximum load current as a function of ambient
temperature and airflow) for horizontal mountings,
efficiency, startup and shutdown parameters, output
ripple and noise, transient response to load step-
change, overload, and short circuit.
Test Conditions
All data presented was taken with the converter
soldered to a test board, specifically a 0.060” thick
printed wiring board (PWB) with four layers. The top
and bottom layers were not metalized. The two inner
layers, comprised of two-ounce copper, were used to
provide traces for connectivity to the converter.
The lack of metallization on the outer layers as well
as the limited thermal connection ensured that heat
transfer from the converter to the PWB was
converters
converter
will
meet
shut
North
down
www.power-one.com
American
under
and
an