Powerint LNK406EG 14W PWM－模拟调光LED驱动方案
2012年01月18日 12:16 发布者：1046235000
Powerin的参考设计DER263是采用LinkSwitchTM-PH系列LNK406EG的14W PWM-模拟调光LED驱动器,LED串的电压电流为28V/500A,输入电压范围从90VAC到265VAC,高效率,230VAC时的PFC大于87%,115VAC时的PFC大于86%,功率因素大于0.9,满足EN61000-3-2 Class C,1000:1调光范围.本文介绍了14W PWM-模拟调光LED驱动器主要特性和指标,电路图,材料清单与PCB布局图.The document describes a high power-factor secondary referenced, analog dimmable LED driver. The circuit is designed to drive a nominal LED string voltage of 28 V at 500 mA from an input voltage range of 90 VAC to 265 VAC. The LED driver utilizes the LNK406EG from the LinkSwitch-PH family of ICs.
Analog dimming is controlled by an external secondary referenced analog control signal of 0-10 V. 0 volts correspond to minimum light output and 10 V corresponds to maximum brightness. The analog controlled signal is transferred to the primary-side and controls the feedback current IFB of LNK406EG which in turn controls the output power/light output of the driver while maintaining high power factor and low THD.
An active load circuit and control are also included to extend dimming ratio beyond 1000:1 but may be omitted if extended dimming operation is not required.
This document contains the LED driver specification, schematic, PCB diagram, bill of materials, conducted EMI measurements, thermal measurements, transformer documentation and typical performance characteristics.
14W PWM-模拟调光LED驱动器主要特性:
High efficiency, power factor corrected
o >87% at 230 VAC and >86% at 115 VAC
o >0.9 PF, meets EN61000-3-2 Class C
0-10 V analog dimming
o >1000:1 dimming range
Low cost, low component count and small printed circuit board footprint
o No current sensing required
o Frequency jitter for smaller, lower cost EMI filter components
Integrated protection and reliability features
o Output open circuit / output short-circuit protected with auto-recovery
o Line input overvoltage shutdown extends voltage withstand during line faults.
o Auto-recovering thermal shutdown with large hysteresis protects both components and printed circuit board
图1.14W PWM-模拟调光LED驱动器外形图:上:顶视图,下:底视图
14W PWM-模拟调光LED驱动器主要指标:
图2.14W PWM-模拟调光LED驱动器电路图
14W PWM-模拟调光LED驱动器材料清单:
图3.变压器框图
图3.14W PWM-模拟调光LED驱动器PCB布局图:上:顶层,下:低层
详情请见:
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LNK406EG：14W PWM模拟调光LED驱动方案
Powerint的参考设计DER263是采用LinkSwitchTM-PH系列LNK406EG的14W PWM-模拟调光LED驱动器，LED串的电压电流为28V/500A，输入电压范围从90VAC~265VAC，高效率，230VAC时的PFC大于87%，115VAC时的PFC大于86%，功率因素大于0.9，满足EN61000-3-2 Class C，1000:1调光范围。
电路可驱动28VLED串电压（500 mA），输入电压范围从90 VAC~265 VAC。该LED驱动器采用了LinkSwitch-PH系列的LNK406EG。
表1 14W PWM-模拟调光LED驱动器主要指标
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模拟调光是通过外部二级模拟控制信号（0V~10V）进行控制，0V为最低亮度，10V为最大亮度。模拟控制信号被传送到初级端，并控制LNK406EG的反馈电流IFB，反过来又控制驱动器的输出功率/光输出，同时又保持高功率因数和低THD。
其有源负载电路和控制用以扩大调光比（1000:1以上），但如果不需要扩展调光也可以省略。
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图1 14W PWM-模拟调光LED驱动器电路图
14W PWM-模拟调光LED驱动器主要特性
•效率高，功率因数校正
– >87％230 VAC时，> 86％在115 VAC
– >0.9PF，符合EN61000-3-2 C级
– -10V模拟调光
• >1000:1的调光范围
•低成本，低元件数量，和小印刷电路
板面积
•无需电流传感
•频率抖动更小，成本更低的EMI滤波器元件
•综合保护与功能可靠
•输出开路/输出短路保护，自动恢复
•线输入过压关断，在线路故障时延伸耐压性。
–自动恢复与热关断，大范围元件和
印刷电路板的滞后保护