- 您现在的位置：买卖IC网 > PDF目录15734 > LM3445TRIACEVAL (National Semiconductor)BOARD EVAL LM3445MM PDF资料下载
参数资料
| 型号： | LM3445TRIACEVAL |
| 厂商： | National Semiconductor |
| 文件页数： | 28/40页 |
| 文件大小： | 0K |
| 描述： | BOARD EVAL LM3445MM |
| 标准包装： | 1 |
| 系列： | PowerWise® |
| 电流 - 输出 / 通道： | 770mA |
| 输出及类型： | 1，非隔离 |
| 特点： | 可调光 |
| 输入电压： | 8 ~ 12V |
| 已供物品： | 板 |
| 已用 IC / 零件： | LM3445MM |
| 相关产品： | LM3445MMX-ND - IC LED DRIVER TRIAC DIMM 10-MSOP LM3445MMDKR-ND - IC LED DRIVER TRIAC DIMM 10-MSOP LM3445MMCT-ND - IC LED DRIVER TRIAC DIMM 10-MSOP LM3445MMTR-ND - IC LED DRIVER TRIAC DIMM 10-MSOP |
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页第21页第22页第23页第24页第25页第26页第27页当前第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
SNVS570L – JANUARY 2009 – REVISED MAY 2013
DESIGN EXAMPLE
The following design example illustrates the process of calculating external component values.
Known:
1. Input voltage range (90V AC – 135V AC )
2. Number of LEDs in series = 7
3. Forward voltage drop of a single LED = 3.6V
4. LED stack voltage = (7 x 3.6V) = 25.2V
Choose:
1. Nominal switching frequency, f SW-TARGET = 250 kHz
2. I LED(AVE) = 400 mA
3. Δ i (usually 15% - 30% of ILED(AVE) ) = (0.30 x 400 mA) = 120 mA
4. Valley fill stages (1,2, or 3) = 2
5. Assumed minimum efficiency = 80%
Calculate:
1. Calculate minimum voltage V BUCK equals:
90 2 x SIN(135 )
V BUCK(MIN) =
2
o
= 45V
(36)
2. Calculate maximum voltage V BUCK equals:
V BUCK(MAX) = 135 2 = 190V
3. Calculate t OFF at V BUCK nominal line voltage:
(37)
u 25.2V
t OFF =
1
1
0.8 115 2
(250 kHz)
= 3.23 P s
(38)
4. Calculate t ON(MIN) at high line to ensure that t ON(MIN) > 200 ns:
u 25.2V
u 25.2V
t ON (MIN) =
1
1
0.8 135 2
1
0.8 135 2
u 3.23 P s = 638 ns
(39)
5. Calculate C11 and R4:
6. Choose current through R4: (between 50 μA and 100 μA) 70 μA
V LED
R4 =
I COLL
= 360 k :
(40)
7. Use a standard value of 365 k ?
8. Calculate C11:
9.
C11 =
V LED
R4
t OFF
1.276
= 175 pF
(41)
10. Use standard value of 120 pF
11. Calculate ripple current: 400 mA X 0.30 = 120 mA
12. Calculate inductor value at t OFF = 3 μs:
u 25.2V
25.2V 1
L2 =
1
0.8 115 2
(350 kHz x 0.1A)
= 580 P H
(42)
13. Choose C10: 1.0 μF 200V
14. Calculate valley-fill capacitor values: V AC low line = 90V AC , V BUCK minimum equals 60V (no triac dimming at
maximum LED current). Set droop for 20V maximum at full load and low line.
28
Product Folder Links: LM3445
Copyright ? 2009–2013, Texas Instruments Incorporated
相关PDF资料 |
PDF描述 |
|---|---|
| VE-B00-EY-F1 | CONVERTER MOD DC/DC 5V 50W |
| ISC1812RXR39K | INDUCTOR WW 390NH 10% 1812 |
| HCM12DSEH | CONN EDGECARD 24POS .156 EYELET |
| MAX6441KADGWD7+T | IC BATTERY MON DUAL SOT23-8 |
| VE-B00-EX-S | CONVERTER MOD DC/DC 5V 75W |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LM3445TRIACEVAL/NOPB | 制造商:Texas Instruments 功能描述:TRIAC Dimmable Offline LED Driver Evaluation Board |
| LM3447 | 制造商:TI 制造商全称:Texas Instruments 功能描述:Phase Dimmable, Primary Side Power Regulated PFC Flyback Controller for LED Lighting |
| LM3447-A19-120VEVM | 功能描述:LED 照明开发工具 LM3447 Eval Mod 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: |
| LM3447-A19-230VEVM | 功能描述:LED 照明开发工具 LM3447 Eval Mod 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: |
| LM3447MT | 制造商:TI 制造商全称:Texas Instruments 功能描述:a Phase-Dimmable, Primary-Side Regulated LED Driver |
发布紧急采购，3分钟左右您将得到回复。