Diodes and Transistors

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Gopi
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Diodes and Transistors

Post by Gopi » Tue Feb 20, 2018 7:35 pm

Hello everyone,

Please see the paper attached.

Gopi
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Diodes and Transistors in the RS.pdf
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Horace
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Re: Diodes and Transistors

Post by Horace » Sun May 20, 2018 12:32 pm

Interesting perspective.

Does it explain the behavior of Drift Step Recovery Diode, in which the diode conducts briefly in reverse and then abruptly stops conducting when "something" becomes purportedly "exhausted" in the PN junction ??

Gopi
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Re: Diodes and Transistors

Post by Gopi » Mon May 21, 2018 10:25 am

Yep, the "something" that gets exhausted is literally the supply of space-to-time or time-to-space, as the reverse bias blocks it. Pulsing the input will make it easier to see this action, but it is essentially like a recoil of a spring. The springiness occurs since the electrons and holes are changing dimensional representations.

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Horace
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Re: Diodes and Transistors

Post by Horace » Tue May 22, 2018 10:44 am

Perhaps your new insight into this phenomena can explain why the best Drift Step Recovery Diodes are old diodes with poorly manufactured PN junctions, in which the spatial transition between the P and N regions is not sharp ...but blurred.
By "best", I mean diodes that "turn off" their pulsed reverse current very abruptly...under a nanosecond. See the Belkin_eng.pdf document in this entry and this one.
It has been observed that the best DSR Diodes have long carrier lifetimes, unfortunately this diode parameter is not given in standard data sheets. In Belkin's document it is denoted by tzh.

Also, why Schottky diodes do not exhibit such rapid step recovery while PN diodes do ?

Gopi
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Re: Diodes and Transistors

Post by Gopi » Thu May 24, 2018 10:01 am

Horace wrote:Also, why Schottky diodes do not exhibit such rapid step recovery while PN diodes do ?
In Schottky diode, there is more "elbow room" because of the large positive displacements of metals. Which means the backwash has more displacement to dissipate in, while in a smeiconductor p-n- junction, it is like a squeezed pipe, so it dries up real quick in the backwash. 2D-->1D is squuezed. 2D-->3D is easier.

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