參數(shù)資料
型號: LM3570SDX
廠商: NATIONAL SEMICONDUCTOR CORP
元件分類: 顯示驅(qū)動器
英文描述: Low Noise White LED Driver System
中文描述: LED DISPLAY DRIVER, DSO14
封裝: 4 X 3 MM, 0.80 MM HEIGHT, LLP-14
文件頁數(shù): 1/13頁
文件大?。?/td> 352K
代理商: LM3570SDX
LM3570
Low Noise White LED Driver System
General Description
The LM3570 device provides a complete LED driver solution
for wireless handsets and other portable devices using a
display and keypad. With three constant current sources, up
to three white LEDs can be used for display lighting with
excellent current matching (0.3% typ.). The regulated 4.35V
output voltage is perfect for driving auxiliary keypad LEDs in
voltage mode.
The LM3570 utilizes a high efficiency 3/2 CMOS charge-
pump with a pre-regulation loop that minimizes conducted
noise on the input. It accepts an input voltage range from
2.7V to 5.5V and maintains a constant current determined by
the current through an external R
SET
resistor.
The device supplies up to 80mA of total load current to
accommodate any combination of up to three white LEDs,
and additional current from V
. The switching frequency is
set at 500kHz. (typ.) to keep the conducted noise spectrum
away from sensitive frequencies within portable RF devices.
By applying a pulse width modulated (PWM) signal to the
PWM pin, the user has the ability to independently control
the brightness of the regulated current source outputs with-
out shutting down the regulated output voltage.
Features
n
2.7V to 5.5V Input Voltage
n
Regulated Output Voltage (V
OUT
= 4.35V)
n
Regulated I
with
±
0.3% matching between constant
current outputs
n
High Efficiency 3/2 Boost function
n
Drives one, two, or three white LEDs with no bias
resistor losses
n
Drives auxiliary keypad LEDS in voltage mode
n
Up to 80mA total output current
n
Active-High Enable
n
Active-High PWM Control Pin for independent control of
current sources
n
Very small solution size
n
1μA(max) shutdown current
n
500kHz switching frequency (typ.)
n
Linear regulation generates predictable noise spectrum
n
LLP-14 package: 4.0mm X 3.0mm X 0.8mm
Applications
n
Portable devices using white or blue LEDs with display
and backlight or frontlight
n
1-Cell LiIon battery-operated equipment including PDAs,
hand-held PCs and cellular phones
Typical Application Circuit
20085021
July 2004
L
2004 National Semiconductor Corporation
DS200850
www.national.com
相關(guān)PDF資料
PDF描述
LM358 Dual Operation Amplifiers
LM358CS Voltage-Feedback Operational Amplifier
LM2904DBLE Voltage-Feedback Operational Amplifier
LM2904S Voltage-Feedback Operational Amplifier
LM2904ND Voltage-Feedback Operational Amplifier
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LM3578 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Switching Regulator
LM3578A 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Switching Regulator
LM3578AM 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
LM3578AM 制造商:Texas Instruments 功能描述:SWITCHED MODE REG SMD 3578 SOIC8
LM3578AM/NOPB 功能描述:直流/直流開關(guān)轉(zhuǎn)換器 SWITCHING REGULATOR 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