參數(shù)資料
型號: PT4856
廠商: Texas Instruments, Inc.
英文描述: "5V/3.3V/1.5V
中文描述: 5V/3.3V/1.5V 輸出 48V 輸入的三路輸出 DC/DC 轉(zhuǎn)換器
文件頁數(shù): 9/13頁
文件大?。?/td> 233K
代理商: PT4856
Application Notes
For technical support and more information, see inside back cover or visit www.ti.com
PT4850 Series
Operating Features of the PT4850 Triple-Output
DC/DC Converters
Over-Current Protection
The PT4850 series of DC/DC converters provide three
independently regulated logic output voltages, Vo
1
, Vo
2
,
and Vo
3
. Each output is current limited to protect against
load faults. The module will not be damaged by a con-
tinuous load fault applied to any output. Current will
continue to flow into the fault but is reduced as the volt-
age across the fault decreases towards zero.
Applying a load fault above the current limit threshold
to any output causes the affected output to significantly
drop. Also load faults applied to Vo
1
will affect Vo
2
and
Vo
3
, once Vo
1
drops to within 0.2V of either of these
voltages. However, load faults applied to Vo
2
or Vo
3
will
not affect the other outputs.
Over-Temperature Protection
The PT4850 DC/DC converter series have an internal
temperature sensor, which monitors the temperature of
the module’s metal case. If the case temperature exceeds
the specified limit the converter will shut down. The
converter will automatically restart when the sensed
temperature returns to within the normal operating
range. The analog voltage generated by the sensor is
also made available at the ‘TEMP’ output (pin 5), and
can be monitored by the host system for diagnostic pur-
poses. Consult the ‘Pin Descriptions’ section of the data
sheet for more information on this feature.
Under-Voltage Lock-Out
The Under-Voltage Lock-Out (UVLO) circuit prevents
operation of the converter whenever the input voltage to
the module is insufficient to maintain output regulation.
The UVLO has approximately 2V of hysterisis. This is
to prevent oscillation with a slowly changing input voltage.
Below the UVLO threshold the module is off and the
enable control inputs, EN1 and EN2 are inoperative.
Primary-Secondary Isolation
The PT4850 series of DC/DC converters incorporate
electrical isolation between the input terminals (primary)
and the output terminals (secondary). All converters are
production tested to a withstand voltage of 1500VDC.
The isolation complies with UL60950 and EN60950,
and the requirements for operational isolation. This
allows the converter to be configured for either a positive
or negative input voltage source.
The regulation control circuitry for these modules is
located on the secondary (output) side of the isolation
barrier. Control signals are passed between the primary
and secondary sides of the converter via a proprietory
magnetic coupling scheme. This eliminates the use of
opto-couplers. The data sheet ‘Pin Descriptions’ and
‘Pin-Out Information’ provides guidance as to which
reference (primary or secondary) that must be used for
each of the external control signals.
Fuse Recommendations
If desired an input fuse may be added to protect against
the application of a reverse input voltage.
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PT4856A 功能描述:直流/直流開關(guān)轉(zhuǎn)換器 5/3.3/1.5V 48V Inp Trpl-Otpt DC-DC Conv RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開關(guān)頻率:1.5 MHz 輸出電壓:4.6 V 輸出電流:250 mA 輸出端數(shù)量:2 最大工作溫度:+ 85 C 安裝風格:SMD/SMT
PT4856C 功能描述:直流/直流開關(guān)轉(zhuǎn)換器 5/3.3/1.5V 48V Inp Trpl-Otpt DC-DC Conv RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開關(guān)頻率:1.5 MHz 輸出電壓:4.6 V 輸出電流:250 mA 輸出端數(shù)量:2 最大工作溫度:+ 85 C 安裝風格:SMD/SMT
PT4856N 功能描述:直流/直流開關(guān)轉(zhuǎn)換器 5/3.3/1.5V 48V Inp Trpl-Otpt DC-DC Conv RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開關(guān)頻率:1.5 MHz 輸出電壓:4.6 V 輸出電流:250 mA 輸出端數(shù)量:2 最大工作溫度:+ 85 C 安裝風格:SMD/SMT
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