原标题：Infineon ILD4001 高效5W LED驱动方案

　　infineon公司的ILD4001是用来驱动大功率LED室内外照明的滞后的降压LED控制器，其内部的推挽输出级能驱动外接N沟MOSFET功率晶体管，LED的电流在350mA到3A,效率高达98%。控制器输入电压4.5V-42V，开关频率高达500kHz，模拟和PWM调光，输出电流精度3%，LED电流的温度漂移非常低，主要用于LED室内外照明，建筑物照明和MR16等LED替代灯以及家用电器等。本文介绍了ILD4001主要特性，方框图，典型应用电路图以及评估板主要指标，电路图和材料清单。

　　The ILD4001 is a hysteretic buck LED controller IC for driving high power LEDs in indoor and outdoor lighting applications.

　　The LED controller is capable of driving an external MOSFET power transistor with the internal push-pull output stage to achieve LED currents of 350 mA up to 3 A and more depending on the dimensioning of the MOSFET, the thermal budget of the circuit board and the current sense resistor.

　　The ILD4001 is widely suitable for LED applications with supply voltages up to 42 V. A multifunctional enable pin allows dimming of the LEDs with DC voltage or a PWM signal. Furthermore the enable pin can be used to switch the LED controller on and off to minimize power consumption in standby.

　　The ILD4001 incorporates an integrated thermal shutdown function pulling low the Vdrive output signal once the junction temperature exceeds the threshold temperature. Once the junction temperature drops below the threshold temperature the Vdrive output is activated again.

　　To provide maximum design flexibility, the ILD4001 is housed in a small SC-74 package.

　　ILD4001主要特性：

　　• Wide input voltage range: 4.5 V ... 42 V

　　• Capable to drive N-channel MOSFETs that provide up to 3 A output current and up to 98% efficiency

　　• Temperature shut down mechanism

　　• Switching frequency up to 500 kHz

　　• Analog and PWM dimming possible

　　• Typical 3 % output current accuracy

　　• Very low LED current drift over temperature

　　• Minimum external component required

　　• Small package: SC-74

　　ILD4001应用：

　　• LED controller for indoor and outdoor illumination

　　• LED replacement lamps, e.g. MR16 halogen replacement

　　• Retail, office and residential high power luminaires

　　• Architectural lighting

　　• Downlights and light engines

　　• Appliances, e.g. fridge / freezer

　　图1。ILD4001方框图

　　图2。ILD4001应用电路图

　　图3。ILD4001采用BSP318S的评估板外形图

　　This document contains information about the LED-Less Demonstration Board for ILD4001. Please refer to the datasheet for the pins descriptions, functions descriptions and specifications.

　　The ILD4001 is a hysteretic buck LED controller IC for industrial applications.

　　The LED Controller is capable to drive external bipolar or MOSFET power transistors by using the internal push-pull output stage.

　　ILD4001 maintains a constant current through a string of LEDs as long as the input voltage exceeds the sum of the forward voltages of the LEDs in the string by at least 3V. The maximum input voltage for this demonstration board must not exceed 30V due to the board is optimizing for the 30V operation. If there is a need to test the board with a maximum supply voltage of 42V, please replace the schottky diode SD1 and the external MOSFET T1 with a suitable breakdown voltage.

　　The precise internal bandgap stabilizes the circuit and provides stable current conditions over temperature range.

　　Furthermore, temperature shut down mechanism enforce the IC to protect attached LEDs.

　　The board includes an “EN/PWM” input terminal for digital or analog dimming control signal.

　　The demonstration board is designed to operate at ambient temperatures up to 100C. Although a wide variety of LED combinations and currents can be driven with the ILD4001, the sense-resistors have to be altered to achieve the desire LED current and inductance has to be changed to attain recommended switching frequencies below 500 kHz.

　　ILD4001评估板主要指标：

　　图4。评估板电路图

　　评估板材料清单：