PTB48520W Datasheet, PDF (8/18 Pages) Texas Instruments – 25-A, 48-V INPUT ISOLATED DC/DC CONVERTER WITH AUTO-TRACK™ SEQUENCING

PTB48520W
SLTS233A – NOVEMBER 2004 – REVISED APRIL 2005
Table 1. Standard Values of R_SET for Common Output Voltages
V_O (Required)
3.6 V
R_SET (Standard Value)
0Ω
V_O (Actual)
3.604 V
3.3 V
887 Ω
3.303 V
2.5 V
6.98 kΩ
2.503 V
2.0 V
35.7 kΩ
2.003 V
1.8 V
Open
1.805 V
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Input Current Limiting
The converter is not internally fused. For safety and overall system protection, the maximum input current to
the converter must be limited. Active or passive current limiting can be used. Passive current limiting can be a
fast-acting fuse. A 125-V fuse, rated no more than 10 A, is recommended. Active current limiting can be
implemented with a current limited Hot-Swap controller.
Thermal Considerations
Airflow may be necessary to ensure that the module can supply the desired load current in environments with
elevated ambient temperatures. The required airflow rate is determined from the safe operating area (SOA). The
SOA is the area beneath the applicable airflow rate curve on the graph of temperature derating vs output current.
(See Typical Characteristics.) Operating the converter within the SOA limits ensures that all the internal
components are at or below their stated maximum operating temperatures.
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