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[SOLVED] Multi emitter BJT transistor

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Hello there! Does anyone know if a multi emitter BJT would work as a regular one (1 emitter) if I shortcircuit all of the emitters' branch? I'm working with an oscillator and I just need a regular BJT but I have found a 2-emitter BJT that fits well with my needs. So, Should I shortcircuit the emitters or use only one of them?

I have the same problem with a N-MOSFET with 2 gates. I need a regular one but this one fits perfectly. Is a multi-gate mosfet with shortcicuited gates similar to having a regular mosfet with only one gate?
 

In most of the cases low power transistors are not multi-emitter, and they use two emitter pins on the package just to allow better PCB design at high frequencies. For example when design LNA's working at microwave frequencies and need to use emitter degeneration inductor, or to decouple the emitter on both sides of the package. In these situations the emitter pins are already short-circuited inside of the package.

As an oscillator the transistor should work fine, even using only one of the emitter pins.
 

Really a dual-emeitter transistor? Many RF transistor have just two emitter pins for low inductamce connection. In any case, you can connect both pins.

A dual-gate MOSFET should be seen as a cascode circuit on a single chip. Shorting G1 and G2 isn't a good idea, better bias G2 with a fixed voltage to take advantage from the dual-gate properties.
 
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there are such things as multiple emitter transistors. Used to use them in digital OR gates. If it really was a multiple emitter transistor, I would hook up the unwanted emitters to a bias source so that they were cut off, in other words, it the base bias was 1 volt DC, I would make the emitters anywhere from 0.4 volts below that to maybe 2 volts above that. That way they are not conducting, have no charges in them, and therefore present a minimum capacitance. Just remember the reverse breakdown voltage of a base/emitter junction is very low...especially for microwave transistors, so use a current limiting resistor if there is any chance of a reverse breakdown.
 
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If you connect bases and collectors of two BJT, you may obtain 2 separated emitter BJT but what it will serve ?? Emitter Currents will be exactly different because of Forward DC Beta differences and it won't serve anything.
In old fashion TTL circuits had multiple emitter configuration but these transistors have been manufactured on the same substrate and same wafer with same emitter width and base area, that's why emitter currents was almost same under certain operating currents.You can't do it by yourself..
 
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Years ago almost all the RF Power Bipolar transistors were multi-emitter, feature which results in high RF current handling capability, high power gain, low base resistance, and low output capacitance.

Because you mentioned an oscillator design, most probably is about a low power device which has two emitter pins attached to the package, for reasons mentioned above.
There is no multi-emitter transistor inside in this situation, just one emitter and two emitter PINS on the package (for example pins 2 and 4 in a SOT343).
 
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Ty very much! I was looking for those kind of answers.
 

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