HBA48T12280 Power-One, HBA48T12280 Datasheet - Page 9

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

minimized. This provides a worst-case but consistent
scenario for thermal derating purposes.
All measurements requiring airflow were made in the
vertical
thermocouples for thermometry.
Ensuring components on the converter do not
exceed their ratings is important in order to maintain
high reliability. If one anticipates operating the
converter at or close to the maximum loads specified
in the derating curves, it is prudent to check actual
derating
Thermographic imaging and thermocouples can be
used. The use of AWG #40 thermocouples is
recommended to ensure measurement accuracy.
Careful routing of the thermocouple leads will further
minimize measurement error.
Thermal Derating
Figure G shows the Output Current versus Baseplate
Temperature. When the user keeps the baseplate at
100°C or, less and a Tamb of 85°C or, less then the
full 12.5 Amps of current is available to the user and
there still is adequate de-rating of the components
on the PCBs. Once the baseplate goes above
100°C, the unit may shut down.
Figure G: Output derating with baseplate temperature vs.
load.
Efficiency
Figure H shows the efficiency vs. load current plot for
ambient temperature of 25 ºC, airflow rate of 300
LFM (1.5 m/s) with horizontal mounting and input
voltages of 36 V, 48 V, 60 V and 75 V.
BCD.00009.1 Rev. AA, 20-Oct-09
14
12
10
8
6
4
2
0
0
and
temperatures
Iload versus Baseplate Temp.
Temp Degrees C
50
horizontal
100
in
wind
the
150
tunnel
application.
Iload Versus
Baseplate Temp.
HBA48T12280 DC-DC Converter Data Sheet
using
36-75 VDC Input; 28 VDC @ 12.5 A Output
Page 9 of 14
Power Dissipation
Figure I
current plot for Ta = 25 ºC, 40 ºC, 55 ºC, 70 ºC, and
85 ºC. LFM was measured at 400 LFM, 300 LFM,
200 LFM, 100 LFM, and 50 LFM. Unit was equipped
with a HSI-502-60H heat sink. The assembly was
vertical mounted and the input voltage was set to 48
VDC.
Figure I: Power dissipation at derated current using
HSI-502-60H heat sink.
Startup
Output voltage waveforms, during the turn-on
transient using the ON/OFF pin and Vcc for full rated
load currents (resistive load) with external load
capacitance of 220 µF are shown in Figure J and
Figure K, respectively.
40
35
30
25
20
15
10
5
0
100
90
80
70
60
50
40
30
20
shows the power dissipation vs. de-rated load
0
10
30
Figure H: Efficiency at 25° Celsius.
20
40
HBA 48T12280 Efficiency
30
Power Dissipation
Ambient Tem (C)
50
40
Load (%)
50
60
60
70
70
www.power-one.com
80
80
90
100
90
400 LFM
300 LFM
200 LFM
100 LFM
50 LFM
36V
48
75V