收藏本站
CAT37
Application Information
Capacitor Selection
MBR0530
Low ESR (equivalent series resistance) capacitors should
be used at the output to minimize the output ripple voltage.
The low ESR and small package options available with
multilayer ceramic capacitors make them excellent choices.
The X5R and X7R capacitor types are preferred because
they retain their capacitance over wider voltage and
temperature ranges than the Y5V or Z5U types. A 1.0 m F
output capacitor is recommended for most applications.
The voltage rating of the output capacitor C2 depends on
the number of LEDs driven in the series. A 16 V ceramic
capacitor is recommended when driving 3 or 4 LEDs.
Low profile ceramic capacitors with a 1 mm maximum
height/thickness are available for designs height
requirements. Ceramic capacitors also make a good choice
for the input capacitor, which should be mounted as close as
Table 6. SCHOTTK Y DIODE SUPPLIERS
Part Supplier
MBR0520 ON Semiconductor
www.onsemi.com
800.282.9855
MBR0540
LED Current Programming
The LED current is programmed with a single resistor
connected to the FB pin. The FB pin is internally regulated
to 95 mV, which sets the current flowing through R1 and the
LEDs as equal to 0.095/R1. For the best accuracy, a 1% or
better resistor is recommended. Table 7 shows several
typical 1% R1 values.
possible to the CAT37. A 1 m F or 4.7 m F input capacitor is
recommended. Table 5 shows a list of several ceramic
capacitor manufacturers. Consult the manufacturers for
detailed information as new products and package options
are introduced regularly.
Table 5. CERAMIC CAPACITOR MANUFACTURERS
Table 7. R1 RESISTOR VALUES
I LED (mA)
40
30
20
R1 ( W )
2.37
3.16
4.75
Supplier
Taiyo Yuden
Murata
Kemet
Web
www.t ? yuden.com
www.murata.com
www.kemet.com
15
12
10
5
6.34
7.87
9.53
19.1
AVX
www.avxcorp.com
For other LED current values, use the following equation
to choose R1.
R1 + 0.095
Diode Selection
Schottky diodes, with their low forward voltage drop and
fast switching speed, are the ideal choice for high efficiency
applications. Table 6 shows several different Schottky
diodes that work well with the CAT37. Make sure that the
diode has a voltage rating greater than the output voltage.
The diode conducts current only when the power switch is
turned off (typically less than one ? third the time), so a 0.4 A
I LED
Most white LEDs are driven at maximum currents of
15 mA to 20 mA. Some higher power designs will use two
parallel strings of LEDs for greater light output, resulting in
30 mA to 40 mA (two strings of 15 mA to 20 mA) flowing
through the R1 resistor.
or 0.5 A diode will be sufficient for most designs.
http://onsemi.com
7
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
CAT4002ASD-GT3 LED DR 2 CH EZ DIM I/F SC-88
CAT4003BTD-GT3 IC LED DVR 3CH TSOT23-6
CAT4004AHU2-GT3B IC LED DVR 4CH EZ DIM I/F 8DFN
CAT4004VP2-T3 IC LED DRIVER LINEAR 8-TDFN
CAT4008W-T2 IC LED DRIVER LINEAR 16-SOIC
CAT4101TV-T75 IC LED DRVR HP CONST CURR D2PAK
CAT4104V-GT3 IC LED DVR 4CH 175MA 8SOIC
CAT4106YP-T2 IC LED DVR 4CH BOOST 16TSSOP
相关代理商/技术参数
CAT37TDI-T3 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:CMOS White LED Driver Boost Converter
CAT37TDI-TE7 功能描述:LED照明驱动器 White LED Boost 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
CAT-38-PP 功能描述:INSTALL TOOL ORANGE FOR SHR SER RoHS:是 类别:工具 >> 螺线形绕线，伸缩套管 系列:- 标准包装:1 系列:Slit-N-Wrap®
CAT-38-PP-BU 功能描述:INSTALL TOOL ORANGE FOR SHR SER RoHS:是 类别:工具 >> 螺线形绕线，伸缩套管 系列:- 标准包装:1 系列:Slit-N-Wrap®
CAT4002A 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:Constant Current LED Driver with 32 Dimming Levels and Rset
CAT4002A_10 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:Constant Current LED Driver with 32 Dimming Levels and Rset
CAT4002ASD-GT3 功能描述:LED照明驱动器 LED DR 2 CH EZ DIM I/F 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
CAT4002ATD-GT3 功能描述:LED照明驱动器 LED DR 2 CH EZ DIM I/F 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