请教FP7208的用法

woaiwojia

我用锂电池驱动一个25V/600mA的LED，用的是FP7208的蕊片，可现在怎么恒流不住，电池从3.4V变动到4.3V，反馈FB引脚电压从0.065V跟着升到0.245V，
想请教一下，是电路不对吗？

超級狗

PWM Dimming Control
The 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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, k! o. A; g, p8 p" n; |& CV_FB = V_EN / 10
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; X1 X* ]7 E' [$ w' V短路掉 EN 上的 1K 電阻 R15 試試看！

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HengliangYau

反馈环路的R13和R16 阻值有点大了

wangshilei

换SY7208 测试一下

1005196332

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