收藏本站
LT3760
APPLICATIONS INFORMATION
lowing the programming of an LED current derating curve
versus the ambient temperature of the LED(s). Without the
ability to back off LED currents as temperature increases,
many LED drivers are limited to driving the LED(s) at 50%
or less of their maximum rated currents. This limitation
requires more LEDs to obtain the intended brightness
for the application. The LT3760 allows the LED(s) to be
programmed for maximum allowable current while still
protecting the LED(s) from excessive currents at high tem-
perature. The temperature breakpoint and the slope of LED
current versus ambient temperature can be programmed
using a simple resistor network shown in Figure 7.
This is achieved by programming a voltage at the CTRL
pin with a negative temperature coefficient using a resistor
divider with temperature dependent resistance (Figures 7
and 8). A variety of resistor networks and NTC resistors
with different temperature coefficients can be used to
achieve the desired CTRL pin voltage behavior versus
temperature. The current derating curve in Figure 6 uses
the resistor network shown in option A of Figure 7.
Table 7 shows a list of NTC resistor manufacturers/ distribu-
tors. There are several other manufacturers available and
the chosen supplier should be contacted for more detailed
information. To use an NTC resistor to monitor the ambient
temperature of the LED(s) it should be placed as close as
possible to the LED(s). Since the temperature dependency
of an NTC resistor can be non-linear over a wide range of
temperatures it is important to obtain a resistor’s exact
values over temperature from the manufacturer. Hand
calculations of CTRL voltage can then be performed at
each given temperature and the resulting CTRL voltage
plotted versus temperature.
Table 7. NTC Resistor Manufacturer s
MANUFACTURER WEB
Murata Electronics North America www.murata.com
TDK Corporation www.tdk.com
Digi-key www.digikey.com
If calculation of CTRL voltage at various temperatures gives
a downward slope that is too strong, alternative resistor
networks can be chosen (B,C,D in Figure 7) which use
temperature independent resistance to reduce the effects
of the NTC resistor over temperature. Murata Electronics
provides a selection of NTC resistors with complete data
over a wide range of temperatures. In addition, a software
tool is available which allows the user to select from dif-
ferent resistor networks and NTC resistor values and then
simulate the exact output voltage curve (CTRL pin behav-
ior) over temperature. Referred to on the website as the
‘Murata Chip NTC Thermistor Output Voltage Simulator’,
1.50
R1
3
1
V REF
CTRL
LT3760
1.25
1.00
R2
OPTION A TO D
R Y
R Y
0.75
0.50
RESISTOR
OPTION A
R NTC
R NTC
R X R NTC
R NTC
R X
0.25
0
10
20
30 40
50
60 70
80
T A - AMBIENT TEMPERATURE (°C)
3760 F08
A
B
C
D
3760 F07
Figure 7. Programming LED Current Derating Curve
vs Ambient Temperature (R NTC Located on LED PCB)
Figure 8. Programmed CTRL Voltage vs Temperature
3760fc
18
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

*
*
*
相关PDF资料
LT3799IMSE#PBF IC LED DRIVER TRIAC DIM 16-MSOP
LT3956EUHE#PBF IC LED DVR BUCK BOOST 36-VQFN
LTC3201EMS#TRPBF IC LED DRVR WHITE BCKLGT 10-MSOP
LTC3202EDD#PBF IC LED DRIVR WHITE BCKLGT 10-DFN
LTC3205EUF#TRPBF IC LED DRVR WT/RGB BCKLGT 24-QFN
LTC3206EUF#TRPBF IC LED DRVR WT/RGB BCKLGT 24-QFN
LTC3207EUF-1#TRPBF IC LED DRIVR QVGA DISPLAY 24-QFN
LTC3208EUH#TRPBF IC LED DRIVR QVGA DISPLAY 32-QFN
相关代理商/技术参数
LT3760EFE#TRPBF 功能描述:IC LED DVR 100MA 8CHAN 28TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - LED 驱动器 系列:- 标准包装:6,000 系列:- 恒定电流:- 恒定电压:- 拓扑:开路漏极，PWM 输出数:4 内部驱动器:是 类型 - 主要:LED 闪烁器 类型 - 次要:- 频率:400kHz 电源电压:2.3 V ~ 5.5 V 输出电压:- 安装类型:表面贴装 封装/外壳:8-VFDFN 裸露焊盘 供应商设备封装:8-HVSON 包装:带卷 (TR) 工作温度:-40°C ~ 85°C 其它名称:935286881118PCA9553TK/02-TPCA9553TK/02-T-ND
LT3760EFEPBF 制造商:LINER 制造商全称:Linear Technology 功能描述:8-Channel × 100mA LED Driver
LT3760EFETRPBF 制造商:LINER 制造商全称:Linear Technology 功能描述:8-Channel × 100mA LED Driver
LT3760IFE 制造商:LINER 制造商全称:Linear Technology 功能描述:8-Channel × 100mA LED Driver
LT3760IFE#PBF 功能描述:IC LED DVR 8CHAN 100MA 28TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - LED 驱动器 系列:- 标准包装:6,000 系列:- 恒定电流:- 恒定电压:- 拓扑:开路漏极，PWM 输出数:4 内部驱动器:是 类型 - 主要:LED 闪烁器 类型 - 次要:- 频率:400kHz 电源电压:2.3 V ~ 5.5 V 输出电压:- 安装类型:表面贴装 封装/外壳:8-VFDFN 裸露焊盘 供应商设备封装:8-HVSON 包装:带卷 (TR) 工作温度:-40°C ~ 85°C 其它名称:935286881118PCA9553TK/02-TPCA9553TK/02-T-ND
LT3760IFE#TRPBF 功能描述:IC LED DVR 100MA 8CHAN 28TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - LED 驱动器 系列:- 标准包装:6,000 系列:- 恒定电流:- 恒定电压:- 拓扑:开路漏极，PWM 输出数:4 内部驱动器:是 类型 - 主要:LED 闪烁器 类型 - 次要:- 频率:400kHz 电源电压:2.3 V ~ 5.5 V 输出电压:- 安装类型:表面贴装 封装/外壳:8-VFDFN 裸露焊盘 供应商设备封装:8-HVSON 包装:带卷 (TR) 工作温度:-40°C ~ 85°C 其它名称:935286881118PCA9553TK/02-TPCA9553TK/02-T-ND
LT3760IFEPBF 制造商:LINER 制造商全称:Linear Technology 功能描述:8-Channel × 100mA LED Driver
LT3760IFETRPBF 制造商:LINER 制造商全称:Linear Technology 功能描述:8-Channel × 100mA LED Driver