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I have 9v AC(1A, 50Hz) as input to 5v DC(500mA) as output rectifier circuit to power up the development board. But I had a doubt if I use Schottky diode instead of normal diode what happens to the circuit. By watching many videos I understand that Schottky diode can operate at high frequency, lower temperature dissipation. But it has more leakage current compared to the normal diode Is that it will affect the rectifier circuit?

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  • \$\begingroup\$ 9Vac seems excessive for a regulated 5V supply. 6Vac might be more efficient. So extra diode drop here is useful and lower cost. unloaded peak is about 50% higher than 9V = 13.5V minus diode dropx2 \$\endgroup\$ Dec 30, 2017 at 19:38
  • \$\begingroup\$ for you, it doesn't matter. normal diodes handle more than schottkys, or at least do so cheaper. \$\endgroup\$
    – dandavis
    Dec 30, 2017 at 19:52
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    \$\begingroup\$ Also, there's the reverse leakage current to consider: electronics.stackexchange.com/questions/44872/… On the other hand, if you somehow need ridiculously low forward drop... \$\endgroup\$ Dec 31, 2017 at 3:52

2 Answers 2

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Traditional diodes are cheaper than schottky diodes and they can usually block a higher voltage in the opposite direction. In most power rectification applications like yours schottky diodes are used to limit voltage drop and power loss.

In your case whether or not you need a schottky diode depends if you need to limit voltage drop or power loss.

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  • \$\begingroup\$ Thanks, Generally schottky diode has more current leakage than traditional diode if i use schottky diode the current leakage will affect the circuit? \$\endgroup\$
    – KARTHICK
    Dec 30, 2017 at 21:38
  • \$\begingroup\$ Both schottky diodes and regular diodes exist in all shapes and sizes, you can get schottky diodes with much lower leakage currents than some traditional diodes it all depends on what you need of your diode. the general rule is read the datasheet, it will tell you how much leakage current you can expect. generally i would say that the voltage drop due to using a traditional diode would give a larger loss of power than the leakage current of a schottky diode. \$\endgroup\$
    – user173292
    Dec 30, 2017 at 21:43
  • \$\begingroup\$ you're welcome (: \$\endgroup\$
    – user173292
    Dec 30, 2017 at 21:46
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The high switching speed of Schottky diodes is not especially useful in rectification. "High frequency", in this context, means frequencies measured in MHz or GHz. 50-60 Hz is a low enough frequency that a normal P-N diode will function acceptably.

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