数据搜索系统，热门电子元器件搜索
  Chinese  ▼
ALLDATASHEETCN.COM

X  

预览 PDF HTML

LP3383 数据表(PDF) 7 Page - Lowpower Semiconductor inc

部件名 LP3383
功能描述  1.2MHzFixed-Frequency PWM Operation
PDF  9 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
制造商  POWER [Lowpower Semiconductor inc]
网页  http://www.lowpowersemi.com
标志 POWER - Lowpower Semiconductor inc

LP3383 数据表(HTML) 7 Page - Lowpower Semiconductor inc

  LP3383 Datasheet HTML 1Page - Lowpower Semiconductor inc LP3383 Datasheet HTML 2Page - Lowpower Semiconductor inc LP3383 Datasheet HTML 3Page - Lowpower Semiconductor inc LP3383 Datasheet HTML 4Page - Lowpower Semiconductor inc LP3383 Datasheet HTML 5Page - Lowpower Semiconductor inc LP3383 Datasheet HTML 6Page - Lowpower Semiconductor inc LP3383 Datasheet HTML 7Page - Lowpower Semiconductor inc LP3383 Datasheet HTML 8Page - Lowpower Semiconductor inc LP3383 Datasheet HTML 9Page - Lowpower Semiconductor inc  
Zoom Inzoom in Zoom Outzoom out
 7 / 9 page
background image
Preliminary Datasheet
LP3383
LP3383 – 00 Version 1.0 Datasheet
OCT.-2012
www.lowpowersemi.com
Page 7 of 9
PWM signal should be higher than the maximum
enable voltage of EN pin, in order to let the
dimming control perform correctly.
Cout
1uF
Cin
10uF
4.7uH
R1
12
Vin
R2
100k
SS14
PWM
EN
4
FB
3
Vin
6
OVP
5
LP3383
0-1MHz
b. Using a DC Voltage
Using a variable DC voltage to adjust the brightness
is a popular method in some applications. The
dimming control using a DC voltage circuit is
shown in Figure 4. According to the Superposition
Theorem, as the DC voltage increases, the voltage
contributed to VFB increases and the voltage drop
on R2 decreases, i.e. the LED current decreases. For
example, if the VDC range is from 0V to 2.8V, the
selection of resistors in Figure 4 sets dimming
control of LED current from 20mA to 0mA.
Cout
1uF
4.7uH
Cin
10uF
R1
12
Vin
R3
56K
R2
6.8K
VDC
SS0520
R4
100k
ON/OFF
EN
4
FB
3
Vin
6
OVP
5
LP3383
c. Using a Filtered PWM signal
Another common application is using a filtered
PWM signal as an adjustable DC voltage for LED
dimming control. A filtered PWM signal acts as the
DC voltage to regulate the output current. The
recomended application circuit is shown in the
Figure 6. In this circuit, the output ripple depends
on the frequency of PWM signal. For smaller output
voltage
ripple (<100mV), the recommended
frequency of 2.8V PWM signal should be above
2kHz. To fix the frequency of PWM signal and
change the duty cycle of PWM signal can get
different
output
current.
According
to
the
application circuit of Figure 5, output current is
from 20.5mA to 5.5mA by adjusting the PWM duty
cycle from 10% to 90%.
Cout
1uF
Cin
10uF
4.7uH
Vin
R4
100k
SS0520
ON/OFF
EN
4
FB
3
Vin
6
OVP
5
LP3383
PWM
R2
6.8K
R1
15
R3
56K
R69
100K
C3
0.1uF
(0-100KHz)



Html Pages

1 2 3 4 5 6 7 8 9


数据表 下载

Go To PDF Page


链接网址



ALLDATASHEET是否为您带来帮助?  [ DONATE ] 

关于 Alldatasheet   |   广告服务   |   联系我们   |   隐私政策   |   数据表链接    |   链接交换   |   制造商名单
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com