收藏本站
LT3597
APPLICATIONS INFORMATION
Table 7 shows a list of manufacturers/distributors of NTC
resistors. There are several other manufacturers avail-
able and the chosen supplier should be contacted for
more detailed information. If an NTC resistor is used to
indicate LED temperature, it is effective only if the resis-
tor is placed as closely as possible to the LED strings.
LED derating curves shown by manufacturers are listed
for ambient temperature. The NTC resistor should have
the same ambient temperature as the LEDs. 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 value over temperature from the
manufacturer. Hand calculations of the CTRLM voltage can
then be performed at each given temperature, resulting in
the CTRLM versus temperature plotted curve. Iterations of
resistor value calculations may be necessary to achieve the
desired break point and slope of the LED current derating
curve. From the CTRLM voltage, the LED current can be
found using the curve shown in Figure 9.
Table 7. NTC Resistor Manufacturers/Distributors
Murata www.murata.com
TDK Corporation www.tdk.com
Digi-Key www.digikey.com
If calculating the CTRLM voltage at various temperatures
gives a downward slope that is too strong, use alternative
resistor networks (B, C, D in Figure 8). They use tempera-
ture independent resistance to reduce the effects of the
NTC resistor over temperature.
120
100
80
60
40
20
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 different resistor networks and NTC
resistor values, and then simulate the exact output volt-
age curve (CTRLM behavior) over temperature. Referred
to as the “Murata Chip NTC Thermistor Output Voltage
Simulator,” users can log onto www.murata.com and
download the software followed by instructions for creat-
ing an output voltage V OUT (CTRLM) from a specified V CC
supply (V REF ).
The CTRLM pin must be tied to V REF if the temperature
derating function is not desired.
Programming Switching Frequency
The switching frequency of the LT3597 can be programmed
between 200kHz and 1MHz by an external resistor con-
nected between the RT pin and ground. Do not leave this
pin open. See Table 8 and Figure 10 for resistor values
and corresponding frequencies.
Table 8. R T Resistor Selection
SWITCHING FREQUENCY (MHz) R T VALUE (k?)
1.0 33.2
0.5 80
0.2 220
1.2
1.0
0.8
0.6
0.4
0.2
0
0
0.25
0.5
0.75 1
1.25
1.5
0
25
50
75
100 125 150 175 200 225
CTRLM (V)
3597 F09
R T (k )
3597 F10
Figure 9. LED Current vs CTRLM Voltage
Figure 10. Programming Switching Frequency
3597fa
15
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
LT3598IUF#PBF IC LED DRIVR WHITE BCKLGT 24-QFN
LT3599IFE#PBF IC LED DRVR WHITE BCKLGT 28TSSOP
LT3743EFE#PBF IC LED DVR HP CONST CURR 28TSSOP
LT3745IUJ#TRPBF IC LED DVR 16CH 50MA 40QFN
LT3746IUHH#TRPBF IC LED DRIVER 32CHANNEL 56-QFN
LT3754IUH#TRPBF IC LED DVR 16CH 50MA 32QFN
LT3755EMSE#PBF IC LED DRVR HP CONS CURR 16-MSOP
LT3760EFE#PBF IC LED DVR WHT/CLR BCKLT 28TSSOP
相关代理商/技术参数
LT3597EUHG#TRPBF 功能描述:IC LED DRIVER 60V TRIPLE 52-QFN 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
LT3597IUHG#PBF 功能描述:IC LED DRIVER 60V TRIPLE 52-QFN 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
LT3597IUHG#TRPBF 功能描述:IC LED DRIVER 60V TRIPLE 52-QFN 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
LT3598 制造商:LINER 制造商全称:Linear Technology 功能描述:60V Triple Step-Down LED Driver Programmable Temperature Protection
LT3598_1 制造商:LINER 制造商全称:Linear Technology 功能描述:6-String 30mA LED Driver with 1.5% Current Matching
LT3598EFE#PBF 功能描述:IC LED DRVR WHITE BCKLGT 24TSSOP 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
LT3598EFE#PBF 制造商:Linear Technology 功能描述:LED DRIVER BOOST PWM 2.5MHZ 制造商:Linear Technology 功能描述:LED DRIVER, BOOST, PWM, 2.5MHZ, TSSOP-24
LT3598EFE#TRPBF 功能描述:IC LED DRVR WHITE BCKLGT 24TSSOP 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