Electrical Engineering Stack Exchange
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Questions tagged [schottky]

A Schottky diode is a diode formed by the junction of a semiconductor with a metal. A Schottky diode has a lower forward voltage drop and faster switching speed than a standard silicon diode.

A Schottky diode typically has a lower forward voltage drop and faster switching speed than a standard silicon diode. A disadvantage is that they usually have a higher leakage current than conventional diodes.

Several forms of transistors such as MESFETs also use the Schottky barrier effect to increase switching speed, while others include a Schottky diode as a form of clamping.

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For a lower voltage drop one could use Schottky diodes, but what are the disadvantages of Schottky's?

In other words, why don't we always use Schottky diodes if they are so much better? What diode properties do Schottky diodes have that makes them unfit for certain applications?
jippie
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Schottky transistor, Not sure I understand it?

So I've been looking through and going through my Digital Computer Electronics book, and I came to this... It seems so simple and I understand the "point" of it, but I'm not sure I understand exactly how it works. "In a Schottky transistor, the…
user3073
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Why is there a Schottky diode connected to the low-side switch

I am trying to understand the reason for having a Schottky diode for protection in a buck switch by reading here. To summarize, I can understand why two the switches should not be turned on at the same time, and I also can understand why there is a…
chami
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Schottky diode like BJT symbol

In this schematic, what do the Schottky diode like "barbs" mean on some of the BJTs where the base is connected? I haven't encountered this symbol before.
jreimers
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Understanding a tachometer signal conditioning circuit I inherited

I have inherited a tachometer signal conditioning circuit. It has an NPN transistor (2N3904) with a Schottky diode (BAT54) between the emitter and the base. It is preceded in the circuit by an LT1017 comparator - so input should be a 5 V square…
Michael Nunan
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Separating USB/MCU power buses

There are two power supply sources in the following diagram - USB and 12V. Only one power supply can be connected at the same time. I am trying to disable power to FT232 whenever 12V is plugged in. In that case FT232 should not be powered, but MCU…
Pablo
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What exactly determines recovery time of Schottky diodes?

I see that low-voltage Schottky diodes have essentially zero recovery time. But would there not still be a small recovery time even for low-voltage Schottky diodes? If so, what determines recovery time there? Some people say capacitance loading is…
Taylor
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Schottky Diode disadvantage as compared to usual diode

Schottky diode have a low forward voltage drop (typically \$0.15-0.45V\$) and very fast switching action, as compared to traditional diode, which typically have a \$0.7V\$ voltage drop (Silicon diodes). What is then the advantage of traditional…
Alexandre Willame
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What does the statement "Schottky diode has high switching speed" mean?

I understand that digital circuits that can be run at high frequency can be called "high speed," but what is the meaning of "Schottky diode having a high switching speed?" Does this describe the maximum slew rate of the output?
quantum231
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How is the asymmetry of a Schottky diode obtained?

A Schottky diode is constructed with two metal conductors bonded to a doped semiconductor. One of the metal-semiconductor junctions is a Schottky contact, and the other metal-semiconductor junction is an Ohmic contact. If the doping in the…
Math Keeps Me Busy
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Is a Schottky diode appropriate for reverse polarity protection?

To narrow the focus a bit from an earlier question: Is a Schottky diode appropriate for reverse polarity protection? I'd like to prevent mishaps from a user connecting DC power in reverse, but I'd also like as low a voltage drop as possible. Can you…
JYelton
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What is a typical diode's ideality factor?

Some background, for anyone unfamiliar: The Shockley diode equation is $$ I_D = I_S·\left(e^{\frac{V_D}{n·V_T}}-1\right) $$ with the quantity \$n\$ called the ideality factor, a number between 1 and 2. Ideal diodes have an ideality factor of 1,…
Hearth
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Adding Diodes to Transistor Astable Multivibrator; 1N5818 Schottky diodes work but 1N4148 diodes don't; can't figure out why

I am an avid electronics hobbyist, not an electronics engineer. I built a transistor-based astable multivibrator circuit and then fed its output to an op amp buffer amplifier which then drove an 8 ohm speaker. Here is an image of the circuit…
Brock R. Wood
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Load Sharing charging circuit for Lithium polymer

Charging lithium battery while at the same time trying to use circuit didn’t quite workout, with problems like the circuit not turning on and the battery never finish charging. The battery is 3.7V and capacity of 300mAH. However I found the…
RS System
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Does the capacitance of a Schottky diode depend on switching frequency?

In datasheets they write '1 MHz' in the capacitance vs voltage figures. For example: I suppose it is some sort of a standard to measure the capacitance at 1 MHz, but is there a dependence of the capacitance on the frequency or is it just the…
Tyo Hoy
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