图中的这个二极管的作用是什么

DING

图中的这个二极管的作用是什么
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pwst

当输入断电后，而输出有大电容，导致还有电压存在，就会造成输出电压大于输入电压，造成器件损伤。这个是保护这个用的。

startostar

保护，前端掉电，后端电压放电路径

超級狗

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2 X/ J. T/ \# A* T  n  R: OUse a Schottky diode
Use a Schottky diode as shown in Figure 3, using a Schottky diode from OUT to IN will keep the body diode in the LDO from conducting when the output voltage exceeds the input voltage. You must use Schottky diodes because of their low forward voltage; traditional diodes have a much higher forward voltage than Schottky diodes. During normal operation, the Schottky diode is reverse biased and will not conduct any current. Another advantage of this approach is that the LDO’s dropout voltage will not increase when placing a Schottky diode between the output and the input.


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liugm668

使用肖特基二极管
7 i' D& P* @! J$ P6 p& s如图三所示，输入输出端用一个肖特基二极管能够使得输出电压高于输入电压的时候防止LDO内部的体二极管导通。你应当用肖特基二极管因为这种管子的前向电压比常规的二极管低很多。在正常操作过程中，这个肖特基二极管是反偏的所以它不会流过电流，采用这种方式的另一个好处是LDO的输入输出端的压降不会因为这个肖特基二极管而增加。

养生之道

学习了，实际使用时还真没注意过这个，芯片手册的参考设计也没见过。

wujiahe829

超級狗 发表于 2022-01-07 10:45:50
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0 h( G+ F6 \8 o- }4 W8 ]; CUse a Schottky diode
Use a Schottky diode as shown in Figure 3, using a Schottky diode from OUT to IN will keep the body diode in the LDO from conducting when the output voltage exceeds the input voltage. You must use Schottky diodes because of their low forward voltage; traditional diodes have a much higher forward voltage than Schottky diodes. During normal operation, the Schottky diode is reverse biased and will not conduct any current. Another advantage of this approach is that the LDO’s dropout voltage will not increase when placing a Schottky diode between the output and the input.
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1 F" _5 A6 I4 J5 p: u" O# V9 A老板，咋哪都有你。

a407715468

66666666666
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shilin

大神解释很到位学习中

haier_ke

学到了

anjingdesenlin

保护器件，前端断电后，可以把后段的电压泄放电

超級狗

wujiahe829 发表于 2022-1-17 17:33
& v7 `* @1 {8 V0 Q. q老板，咋哪都有你。

沒錢收骨董、字畫，只能撿些破爛！

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没有星星的夜空

学到了，感谢大佬