參數(shù)資料
型號(hào): LM2653
文件頁數(shù): 1/11頁
文件大?。?/td> 215K
代理商: LM2653
LM2650
Synchronous Step-Down DC/DC Converter
General Description
The LM2650 is a step-down DC/DC converter featuring high
efficiency over a 3A to milliamperes load range. This feature
makes the LM2650 an ideal fit in battery-powered applica-
tions that demand long battery life in both run and standby
modes.
The LM2650 also features a logic-controlled shutdown mode
in which it draws at most 25μA from the input power supply.
The LM2650 employs a fixed-frequency pulse-width modu-
lation (PWM) and synchronous rectification to achieve very
high efficiencies. In many applications, efficiencies reach
95%+ for loads around 1A and exceed 90% for moderate to
heavy loads from 0.2A to 2A.
A low-power hysteretic or
sleep
mode keeps efficiencies
high at light loads. The LM2650 enters and exits sleep mode
automatically as the load crosses
sleep in
and
sleep out
thresholds. The LM2650 provides nodes for programming
both thresholds via external resistors.Alogic input allows the
user to override the automatic sleep feature and keep the
LM2650 in PWM mode regardless of the load level.
An optional soft-start feature limits current surges from the
input power supply at start up and provides a simple means
of sequencing multiple power supplies.
Features
n
Ultra high efficiencies (95% possible)
n
High efficiency over a 3A to milliamperes load range
n
Synchronous switching of internal NMOS power FETs
n
Wide input voltage range (4.5V to 18V)
n
Output voltage adjustable from 1.5V to 16V
n
Automatic low-power sleep mode
n
Logic-controlled micropower shutdown (I
QSD
25 μA)
n
Frequency adjustable up to 300 kHz
n
Frequency synchronization with external signal
n
Programmable soft-start
n
Short-circuit current limiting
n
Thermal shutdown
n
Available in 24-lead Small-Outline package
Applications
n
Notebook and palmtop personal computers
n
Portable data terminals
n
Modems
n
Portable Instruments
n
Global positioning devices (GPSs)
n
Battery-powered digital devices
Typical Application
DS012848-1
Converting a Four-Cell Li Ion Battery to 5V
LM2650-ADJ Efficiency
DS012848-2
November 2000
L
2000 National Semiconductor Corporation
DS012848
www.national.com
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LM2653_05 制造商:NSC 制造商全稱:National Semiconductor 功能描述:1.5A High Efficiency Synchronous Switching Regulator
LM2653-ADJEVAL 功能描述:電源管理IC開發(fā)工具 EVAL BOARDFOR LM2653 RoHS:否 制造商:Maxim Integrated 產(chǎn)品:Evaluation Kits 類型:Battery Management 工具用于評(píng)估:MAX17710GB 輸入電壓: 輸出電壓:1.8 V
LM2653MTC-ADJ 功能描述:直流/直流開關(guān)轉(zhuǎn)換器 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(fēng)格:SMD/SMT
LM2653MTC-ADJ/NOPB 功能描述:直流/直流開關(guān)轉(zhuǎn)換器 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(fēng)格:SMD/SMT
LM2653MTCX-ADJ 功能描述:直流/直流開關(guān)轉(zhuǎn)換器 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(fēng)格:SMD/SMT