- 您现在的位置：买卖IC网 > PDF目录17193 > LM3423BBLSCSEV/NOPB (National Semiconductor)BOARD EVAL BUCK BOOST LM3423 PDF资料下载
参数资料
| 型号： | LM3423BBLSCSEV/NOPB |
| 厂商： | National Semiconductor |
| 文件页数： | 21/67页 |
| 文件大小： | 0K |
| 描述： | BOARD EVAL BUCK BOOST LM3423 |
| 标准包装： | 1 |
| 系列： | PowerWise® |
| 电流 - 输出 / 通道： | 700mA |
| 输出及类型： | 1，非隔离 |
| 输入电压： | 10 ~ 70 V |
| 已供物品： | 板，文档 |
| 已用 IC / 零件： | LM3423 |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页当前第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页第36页第37页第38页第39页第40页第41页第42页第43页第44页第45页第46页第47页第48页第49页第50页第51页第52页第53页第54页第55页第56页第57页第58页第59页第60页第61页第62页第63页第64页第65页第66页第67页
SNVS574E – JULY 2008 – REVISED MAY 2013
= 1 . 24V x ¨ ¨ UV 1
R UV 1
V TURN
-
ON
?
§ R + R UV 2 ·
?
? 1
(29)
The hysteresis (V HYS ) is defined as follows:
UVLO only
V HYS = 23 P A x R UV 2
PWM dimming and UVLO
(30)
V HYS = 23 P A x ¨ ¨ R UV 2 + UVH
x ( R UV 1 + R UV 2 ) ·
?
1
§ R
?
R UV 1
?
(31)
When "zero current" shutdown and UVLO are implemented together, the EN pin can be used to escape UVLO.
The nDIM pin will pull-up to V IN when EN is pulled low, therefore if V IN is within the UVLO hysteretic window
when EN is pulled high again, the controller will start-up even though V TURN-ON is not exceeded.
PWM DIMMING
The active low nDIM pin can be driven with a PWM signal which controls the main NFET and the dimming FET
(dimFET). The brightness of the LEDs can be varied by modulating the duty cycle of this signal. LED brightness
is approximately proportional to the PWM signal duty cycle, (i.e. 30% duty cycle ~ 30% LED brightness). This
function can be ignored if PWM dimming is not required by using nDIM solely as a V IN UVLO input as described
in the INPUT UNDER-VOLTAGE LOCKOUT (UVLO) section or by tying it directly to V CC or V IN .
Inverted
V IN
R UV2
R UV1
PWM
D DIM
R UVH
LM3421/23
nDIM
Q DIM
Standard
PWM
Figure 29. PWM Dimming Circuit
1. Connect the dimming MosFET (Q DIM ) with the drain to the nDIM pin and the source to AGND. Apply an
external logic-level PWM signal to the gate of Q DIM .
2. Connect the anode of a Schottky diode (D DIM ) to the nDIM pin. Apply an inverted external logic-level PWM
signal to the cathode of the same diode.
The DDRV pin is a PWM output that follows the nDIM PWM input signal. When the nDIM pin rises, the DDRV pin
rises and the PWM latch reset signal is removed allowing the main MosFET Q1 to turn on at the beginning of the
next clock set pulse. In boost and buck-boost topologies, the DDRV pin is used to control a N-channel MosFET
placed in series with the LED load, while it would control a P-channel MosFET in parallel with the load for a buck
topology.
Copyright ? 2008–2013, Texas Instruments Incorporated
21
Product Folder Links: LM3421 LM3421-Q1 LM3423 LM3423-Q1
相关PDF资料 |
PDF描述 |
|---|---|
| GCA10DRMI-S288 | CONN EDGECARD 20POS .125 EXTEND |
| ESM06DTKN-S288 | CONN EDGECARD 12POS .156 EXTEND |
| RNM-1509S | CONV DC/DC 1W 15VIN 09VOUT |
| T95Z156K025CZSL | CAP TANT 15UF 25V 10% 2910 |
| ESM06DTKH-S288 | CONN EDGECARD 12POS .156 EXTEND |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LM3423BS2LYEV/NOPB | 功能描述:LED 照明开发工具 LM3423BS2LY EVAL BOARD RoHS:否 制造商:Fairchild Semiconductor 产品:Evaluation Kits 用于:FL7732 核心: 电源电压:120V 系列: 封装: |
| LM3423MH | 制造商:Texas Instruments 功能描述:LED DRVR 3Segment 5V/9V/12V/15V/18V/24V 20-Pin TSSOP EP Rail 制造商:Texas Instruments 功能描述:LED DRIVER, HI V, 4.5~75V, POWERWISE |
| LM3423MH/NOPB | 功能描述:LED照明驱动器 RoHS:否 制造商:STMicroelectronics 输入电压:11.5 V to 23 V 工作频率: 最大电源电流:1.7 mA 输出电流: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:SO-16N |
| LM3423MHBKBSTEV | 制造商:Texas Instruments 功能描述:Development Kits And Tools, The Lm3421/23 Are Versatile High Voltage N-Channel Mosfet Controllers For LED Drivers Evaluation Board |
| LM3423MHBKBSTEV/NOPB | 功能描述:BOARD EVAL BUCK BOOST LM3423 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 |
发布紧急采购，3分钟左右您将得到回复。