Datasheet > LM2794

LM2794

更新时间： 2024-11-12 22:51:43

品牌	Logo	应用领域
美国国家半导体 - NSC		开关
页数	文件大小	规格书
16页	484K
描述
Current Regulated Switched Capacitor LED Supply with Analog and PWM Brightness Control

阅读下载

中文翻译

获取价格

数据手册

如果您发现信息不准确，欢迎纠错

LM2794 数据手册

March 2004

LM2794/LM2795

Current Regulated Switched Capacitor LED Supply with

Analog and PWM Brightness Control

General Description

Features

n Regulated current sources with 0.5% matching

between any two outputs

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.

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

The LM2794/5 delivers up to 80mA of 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.

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

DS200285

www.national.com

12 3 4 5 6 7...16

中文翻译

下载PDF

与LM2794相关器件

型号	品牌	获取价格	描述	数据表
LM2794BL	NSC	获取价格	Current Regulated Switched Capacitor LED Supply with Analog and PWM Brightness Control
LM2794BL/NOPB	TI	获取价格	SWITCHED CAPACITOR REGULATOR, 675kHz SWITCHING FREQ-MAX, PBGA14, LEAD FREE, CSP-14
LM2794BLX	NSC	获取价格	Current Regulated Switched Capacitor LED Supply with Analog and PWM Brightness Control
LM2794TL	NSC	获取价格	Current Regulated Switched Capacitor LED Supply with Analog and PWM Brightness Control
LM2794TL/NOPB	TI	获取价格	具有模拟和 PWM 亮度控制功能的电流调节开关电容器 LED 电源 \| YPA \| 14
LM2794TLX	NSC	获取价格	Current Regulated Switched Capacitor LED Supply with Analog and PWM Brightness Control
LM2795	ETC	获取价格
LM27951	NSC	获取价格	White LED Adaptive 1.5X/1X Switched Capacitor Current Driver
LM27951	TI	获取价格	输入电压范围为 2.8V-5.5V 的白光 LED 自适应 1.5X/1X 开关电容器电流
LM27951SD	NSC	获取价格	White LED Adaptive 1.5X/1X Switched Capacitor Current Driver