收藏本站
参数资料
型号： NUD4011
厂商： ON SEMICONDUCTOR
英文描述： Low Current LED Driver(低电流LED驱动器)
中文描述： 低电流LED驱动器（低电流的LED驱动器）
文件页数： 5/9页
文件大小： 133K
代理商： NUD4011
NUD4011
http://onsemi.com
5
APPLICATION INFORMATION (continued)
Design Guide for AC Applications
1. Define LED’s current:
a. I
LED
= 30 mA
2. Define V
in
:
a. Per example in Figure 5, V
in
= 120 Vac
3. Define V
LED
@ I
LED
per LED supplier’s data
sheet:
a. Per example in Figure 6,
V
LED
= 3.0 V (30 LEDs in series)
V
LEDs
= 90 V
4. Calculate Resistor Value for R
ext
:
The calculation of the R
ext
for AC applications is
totally different than for DC. This is because
current conduction only occurs during the time
that the ac cycles’ amplitude is higher than V
LEDs
.
Therefore R
ext
calculation is now dependent on the
peak current value and the conduction time.
a. Calculate for V
LEDs
= 90 V:
V = V
peak
Sin
90 V = (120
2
)
= 32.027
°
b. Calculate conduction time for
= 32.027
°
. For
a sinuousoidal waveform Vpeak happens at
= 90
°
. This translates to 4.165 ms in time for
a 60 Hz frequency, therefore 32.027
°
is 1.48 ms
and finally:
Conduction time = (4.165 ms – 1.48 ms)
= 5.37 ms
c. Calculate the I
peak
needed for I
(avg)
= 30 mA
Since a full bridge rectifier is being used (per
Figure 6), the frequency of the voltage signal
applied to the NUD4011 device is now 120 Hz.
To simplify the calculation, it is assumed that
the 120 Hz waveform is square shaped so that
the following formula can be used:
I
(avg)
= I
peak
duty cycle;
If 8.33 ms is 100% duty cycle, then 5.37 ms is
64.46%, then:
I
peak
= I
(avg)
/ duty cycle
I
peak
= 30 mA / 0.645 = 46 mA
d. Calculate R
ext
R
ext
= 0.7 V / I
peak
R
ext
= 15.21
Sin
2
5. Calculate V
drop
across the NUD4011 device:
a. V
drop
= V
in
– V
sense
– V
LEDs
b. V
drop
= 120 V – 0.7 V – 90 V
c. V
drop
= 29.3 V
Figure 6. 120 Vac Application
(Series LED’s array)
R
ext
PWM
V
in
1
I
out
8
Current
Set Point
NUD4011
Boost
I
out
7
I
out
6
I
out
5
2
3
4
L
ED1
L
ED2
L
ED30
Full
Bridge
Rectifier
120 Vac
60 Hz
+
1
2
3
4
6. Calculate Power Dissipation on the NUD4011
device’s driver:
a. P
D_driver
= V
drop
* I
(avg)
b. P
D_driver
= 29.3 V
c. P
D_driver
= 0.879 W
0.030 A
7. Establish Power Dissipation on the
NUD4011device’s control circuit per below
formula:
a. P
D_control
= (V
in
– 1.4 – V
LEDs
) / 20,000
b. P
D_control
= 0.040 W
8. Calculate Total Power Dissipation on the device:
a. P
D_total
= P
D_driver
+ P
D_control
b. P
D_total
= 0.879 W + 0.040 W = 0.919 W
9. If P
D_total
> 1.13 W (or derated value per
Figure 3), then select the most appropriate
recourse and repeat steps 1
8:
a. Reduce V
in
b. Reconfigure LED array to reduce V
drop
c. Reduce I
out
by increasing R
ext
d. Use external resistors or parallel device’s
configuration
10. Calculate the junction temperature using the
thermal information on Page 8 and refer to
Figure 4 to check the output current drop due to
the calculated junction temperature. If desired,
compensate it by adjusting the value of R
ext
.
相关PDF资料
PDF描述
NUF2015W1 USB Upstream Terminator with ESD Protection(带ESD保护的USB上游终端)
NUF2070MN 2 Line Audio EMI Filter with ESD Protection(2线音频EMI滤波器,带ESD保护)
NUF2101M USB Filter with ESD Protection(USB 1.1 下行EMI滤波器，带ESD保护器)
NUF2220XV6 2 Line EMI Filter with ESD Protection(2线EMI滤波器带ESD保护)
NUF2221W1T2G USB Upstream Terminator with ESD Protection
相关代理商/技术参数
参数描述
NUD4011/D 制造商:未知厂家 制造商全称:未知厂家 功能描述:Low Current LED Driver
NUD4011DR2 功能描述:LED照明驱动器 Low Current LED 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
NUD4011DR2G 功能描述:LED照明驱动器 MI LO CUR LED DRVR 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
NUD4011DR2G-CUT TAPE 制造商:ON 功能描述:NUD4011 Series 70 mA 200 V Surface Mount Low Current LED Driver - SOIC-8
NUD4301 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:Dual Channel LED Driver/Current Source
发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

*型号 *数量 厂商 批号 封装
添加更多采购

我的联系方式

*
*
*