- 您现在的位置：买卖IC网 > PDF目录224108 > LM3402_07 (National Semiconductor Corporation) 0.5A Constant Current Buck Regulator for Driving High Power LEDs PDF资料下载
参数资料
| 型号： | LM3402_07 |
| 厂商： | National Semiconductor Corporation |
| 英文描述： | 0.5A Constant Current Buck Regulator for Driving High Power LEDs |
| 中文描述： | 0.5A的恒流降压稳压器用于驱动高功率LED |
| 文件页数： | 2/24页 |
| 文件大小： | 431K |
| 代理商： | LM3402_07 |
Block Diagram
20192103
Application Information
THEORY OF OPERATION
The LM3402 and LM3402HV are buck regulators with a wide
input voltage range, low voltage reference, and a fast output
enable/disable function. These features combine to make
them ideal for use as a constant current source for LEDs with
forward currents as high as 500 mA. The controlled on-time
(COT) architecture is a combination of hysteretic mode con-
trol and a one-shot on-timer that varies inversely with input
voltage. Hysteretic operation eliminates the need for small-
signal control loop compensation. When the converter runs in
continuous conduction mode (CCM) the controlled on-time
maintains a constant switching frequency over the range of
input voltage. Fast transient response, PWM dimming, a low
power shutdown mode, and simple output overvoltage pro-
tection round out the functions of the LM3402/02HV.
CONTROLLED ON-TIME OVERVIEW
Figure 1 shows the feedback system used to control the cur-
rent through an array of LEDs. A voltage signal, V
SNS, is
created as the LED current flows through the current setting
resistor, R
SNS, to ground. VSNS is fed back to the CS pin,
where it is compared against a 200 mV reference, V
REF. The
on-comparator turns on the power MOSFET when V
SNS falls
below V
REF. The power MOSFET conducts for a controlled
on-time, t
ON, set by an external resistor, RON, and by the input
voltage, V
IN. On-time is governed by the following equation:
At the conclusion of t
ON the power MOSFET turns off for a
minimum off-time, t
OFF-MIN, of 300 ns. Once tOFF-MIN is com-
plete the CS comparator compares V
SNS and VREF again,
waiting to begin the next cycle.
www.national.com
10
LM3402/LM3402HV
相关PDF资料 |
PDF描述 |
|---|---|
| LM4681SQ | 10 Watt Stereo CLASS D Audio Power Amplifier with Stereo Headphone Amplifier and I2C/SPI Volume Control |
| LM5009SD | 150 mA, 100V Step-Down Switching Regulator |
| LM5009SDX | 150 mA, 100V Step-Down Switching Regulator |
| LMK02000 | Precision Clock Conditioner with Integrated PLL |
| LMR-01-Z | SPECIAL SWITCH-JOYSTICK SWITCH, SPDT, MOMENTARY, 1A, 14VDC, PANEL MOUNT |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LM3402EVAL | 功能描述:BOARD EVALUATION FOR LM3402 RoHS:是 类别:编程器，开发系统 >> 评估板 - LED 驱动器 系列:PowerWise® 标准包装:1 系列:PowerWise® 电流 - 输出 / 通道:20mA 输出及类型:1，非隔离 输出电压:17V 特点:可调光 输入电压:2.7 ~ 5.5 V 已供物品:板 已用 IC / 零件:LM3508 相关产品:LM3508TLX-ND - IC LED DRVR WHT BCKLGT 9USMDLM3508TLDKR-ND - IC LED DRVR WHT BCKLGT 9MICROSMDLM3508TLCT-ND - IC LED DRVR WHT BCKLGT 9MICROSMDLM3508TLTR-ND - IC LED DRVR WHT BCKLGT 9MICROSMD |
| LM3402EVAL | 制造商:Texas Instruments 功能描述:EVAL BOARD |
| LM3402EVAL/NOPB | 功能描述:电源管理IC开发工具 LM3402 EVAL BOARD RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V |
| LM3402HV | 制造商:Texas Instruments 功能描述:Buck Regulator ,0.5A ,LED Drivers,MSOP8 |
| LM3402HVEVAL | 功能描述:BOARD EVALUATION FOR LM3402HV RoHS:是 类别:编程器，开发系统 >> 评估板 - LED 驱动器 系列:PowerSmart® 标准包装:1 系列:PowerWise® 电流 - 输出 / 通道:20mA 输出及类型:1，非隔离 输出电压:17V 特点:可调光 输入电压:2.7 ~ 5.5 V 已供物品:板 已用 IC / 零件:LM3508 相关产品:LM3508TLX-ND - IC LED DRVR WHT BCKLGT 9USMDLM3508TLDKR-ND - IC LED DRVR WHT BCKLGT 9MICROSMDLM3508TLCT-ND - IC LED DRVR WHT BCKLGT 9MICROSMDLM3508TLTR-ND - IC LED DRVR WHT BCKLGT 9MICROSMD |
发布紧急采购，3分钟左右您将得到回复。