參數(shù)資料
型號: LM2794TLX
廠商: NATIONAL SEMICONDUCTOR CORP
元件分類: 穩(wěn)壓器
英文描述: Current Regulated Switched Capacitor LED Supply with Analog and PWM Brightness Control
中文描述: SWITCHED CAPACITOR REGULATOR, 675 kHz SWITCHING FREQ-MAX, PBGA14
封裝: CSP-14
文件頁數(shù): 1/16頁
文件大?。?/td> 487K
代理商: LM2794TLX
LM2794/LM2795
Current Regulated Switched Capacitor LED Supply with
Analog and PWM Brightness Control
General Description
The LM2794/95 is a fractional CMOS charge-pump that
provides four regulated current sources. It accepts an input
voltage range from 2.7V to 5.5V and maintains a constant
current determined by an external sense resistor.
The LM2794/5 delivers up to 80mAof load current to accom-
modate four White LEDs. The switching frequency is
325kHz. (min.) to keep the conducted noise spectrum away
from sensitive frequencies within portable RF devices.
Brightness can be controlled by both linear and PWM tech-
niques. A voltage between 0V and 3.0V may be applied to
the BRGT pin to linearly vary the LED current. Alternatively,
a PWM signal can be applied to the SD pin to vary the
perceived brightness of the LED. The SD pin reduces the
operating current to 2.3μA (typ.) The LM2794 is shut down
when the SD pin is low, and the LM2795 is shut down when
the SD pin is high.
The LM2794/95 is available in a micro SMD-14 CSP pack-
age.
Features
n
Regulated current sources with
±
0.5% matching
between any two outputs
n
High efficiency 3/2 boost function
n
Drives one, two, three or four white LEDs
n
2.7V to 5.5V Input Voltage
n
Up to 80mA output current
n
Analog brightness control
n
Active-low or high shutdown input (’94/95)
n
Very small solution size and no inductor
n
2.3μA (typ.) shutdown current
n
325kHz switching frequency (min.)
n
Constant Frequency generates predictable noise
spectrum
n
Standard Micro SMD-14 package: 2.08mm X 2.403mm
X 0.845mm High
n
Thin Micro SMD-14 package: 2.08mm X 2.403mm X
0.600mm High
Applications
n
White LED Display Backlights
n
White LED Keypad Backlights
n
1-Cell Li-Ion battery-operated equipment including
PDAs, hand-held PCs, cellular phones
Basic Application Circuit
20028503
March 2004
L
B
2004 National Semiconductor Corporation
DS200285
www.national.com
相關(guān)PDF資料
PDF描述
LM2794BL Current Regulated Switched Capacitor LED Supply with Analog and PWM Brightness Control
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LM27952 White LED Adaptive 1.5X/1X Switched Capacitor Current Driver
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LM2794TLX/NOPB 功能描述:LED照明驅(qū)動器 RoHS:否 制造商:STMicroelectronics 輸入電壓:11.5 V to 23 V 工作頻率: 最大電源電流:1.7 mA 輸出電流: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SO-16N
LM2795 制造商:未知廠家 制造商全稱:未知廠家 功能描述:
LM27951 制造商:NSC 制造商全稱:National Semiconductor 功能描述:White LED Adaptive 1.5X/1X Switched Capacitor Current Driver
LM27951SD 功能描述:LED照明驅(qū)動器 RoHS:否 制造商:STMicroelectronics 輸入電壓:11.5 V to 23 V 工作頻率: 最大電源電流:1.7 mA 輸出電流: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SO-16N
LM27951SD/NOPB 功能描述:LED照明驅(qū)動器 RoHS:否 制造商:STMicroelectronics 輸入電壓:11.5 V to 23 V 工作頻率: 最大電源電流:1.7 mA 輸出電流: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SO-16N