Catalyst的CAT4201是高效率的降压转换器,用来驱车大电流的LED.CAT4201所采用的正在申请专利的开关控制算法使它具有高效率和精确的LED电流.它的LED驱动电流可高达350mA,电源电压和12V与24V系统兼容.5引脚的SOT23封装使它可用在空间受到限制的地方.解决方案给出了它的方框图,典型应用电路图以及LED串联与为了驱动大电流LED的CAT4201并联应用电路图.

The CAT4201 is a high efficiency step-down converter optimized to drive high current LEDs. A patent-pending switching control algorithm allows highly efficient and accurate LED current regulation. A single RSET resistor sets the full scale LED string current up to 350mA from supplies as high as 28V.

The switching architecture of the CAT4201 results in extremely low internal power dissipation allowing the device to be housed in a tiny package without the need for dedicated heat sinking. The device is compatible with switching frequencies of up to 1MHz, making it ideal for applications requiring small footprint and low value external inductors.

Analog dimming and LED shutdown control is provided via a single input pin, CTRL. Additional
features include overload current protection and thermal shutdown. The device is available in the low profile 5-lead thin SOT23 package and is ideal for space constrained applications.

主要特性:

LED drive current up to 350mA
12V and 24V system compatible
Handles transients up to 40V
Single Pin Control and Dimming function
Power Efficiency up to 94%
Drives LED strings of up to 20 volts
Open and short LED protection
Parallel configuration for higher output current
RoHS-compliant TSOT-23 5-lead package

应用:

12V and 24V Lighting Systems
Automotive and Aircraft Lighting
General lighting
High Brightness 350mA LEDs

Fig. 1. CAT4201简化的方框图:



Fig.2 典型应用电路图:



Fig3. 5个LED 24V 应用电路图



Figure 4. 三个CAT4201并联,用来驱动1A的LED



详情请上网:

http://www.catsemi.com/datasheets/4201.pdf