原标题：安森美NCP3065高亮度LED电源方案

　　安森美公司的NCP3065是集成了1.5A开关的单片开关稳压器,可以配置成降压模式或升压模式.它的输入电压从3V到40V,能为高亮度LED(HBLED)提供恒流的电源.反馈电压低到235mV,可以逐个周期地限流,广泛应用在汽车和船舶照明,大功率LED驱动器,恒流源以及低压LED照明.本文介绍了NCP3065的主要性能,应用电路以及评估板电路图和所用的材料清单(BOM).

　　The NCP3065 is a monolithic switching regulator designed to deliver constant current for powering high brightness LEDs (HBLED). The device has a very low feedback voltage of 235 mV (nominal) which is used to regulate the average current of the LED string. In addition, the NCP3065 has a wide input voltage up to 40 V to allow it to operate from 12 Vac or 12 Vdc supplies commonly used for lighting applications as well as unregulated supplies such as Lead Acid batteries.

　　The device can be configured in a controller topology with the addition of an external transistor to support higher LED currents beyond the 1.5 A rated switch current of the internal transistor. The NCP3065 switching regulator can be configured in Step-Down (Buck) and Step-Up (boost) topologies with a minimum number of external components.

　　特性:

　　Integrated 1.5 A Switch

　　Input Voltage Range from 3 V to 40 V

　　Low Feedback Voltage of 235 mV

　　Cycle-by-Cycle Current Limit

　　No Control Loop Compensation Required

　　Frequency of Operation Adjustable up to 250 kHz

　　Operation With All Ceramic Output Capacitors or No Output

　　Capacitance

　　Analog and Digital PWM Dimming Capability

　　Internal Thermal Shutdown with Hysteresis

　　应用:

　　Automotive and Marine Lighting

　　High Power LED Driver

　　Constant Current Source

　　Low Voltage LED Lighting(Landscape, Path, Solar, MR16 Replacement)

图1. NCP3065方框图

图2. NCP3065典型应电路

图3.NCP3065 3A降压评估板电路图

　　表1.NCP3065 3A降压评估板元件清单(BOM)