PWM Dimming Control
  `! |9 l5 u" ]# [, QThe PWM signal is connected to EN pin to adjust the feedback voltage (VFB) then LED current is also changed. The EN pin is built-in components of filter to regulate PWM signal become a DC voltage. The DC voltage is valid from 0.25V to 2.25V. The feedback voltage and LED current keep constant when the DC voltage is higher than 2.25V. The PWM signal is recommended above 10KHz.
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V_FB = V_EN / 10
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* {$ J+ L* ]1 j+ g4 a  B; q& M- C短路掉 EN 上的 1K 電阻 R15 試試看！

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换SY7208 测试一下

反馈环路的R13和R16 阻值有点大了