### Author Topic: What is the meaning of Vceo, Vcbo and Vebo in Transistor?  (Read 14749 times)

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#### Walt Peter

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##### What is the meaning of Vceo, Vcbo and Vebo in Transistor?
« on: March 18, 2016, 11:24:31 pm »
In transistor, does Vceo means the total voltage of Collector and Emitter? And Vcbo means the total voltage of Collector and Base? And Vebo means the total voltage of Emitter and Base? Thank you.

#### Ian.M

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##### Re: What is the meaning of Vceo, Vcbo and Vebo in Transistor?
« Reply #1 on: March 18, 2016, 11:31:40 pm »
No.  All voltages are measured as voltage differences.  The transistor's leads are b,c and e.  o means open circuit.  Voltages given in the V--o form are usually maximum ratings.

Therefore Vceo is the maximum voltage the transistor can withstand on its collector measured relative to its emitter with the base open circuit.  It is likely to be less than Vcbo because leakage across the reverse biassed collector base junction provides base current that starts to turn the transistor on.   With the emitter open circuit there is no transistor action and the collector base junction acts as a simple diode.

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#### Walt Peter

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##### Re: What is the meaning of Vceo, Vcbo and Vebo in Transistor?
« Reply #2 on: March 18, 2016, 11:40:51 pm »
How can I calculate the V__o? Thank you.

#### Ian.M

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##### Re: What is the meaning of Vceo, Vcbo and Vebo in Transistor?
« Reply #3 on: March 18, 2016, 11:54:40 pm »
No such thing.  I was using V--o as a generic description of the parameters Vceo, Vcbo and Vebo.  None of them are calculable, they have to be looked up in the datasheet.

#### Brumby

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##### Re: What is the meaning of Vceo, Vcbo and Vebo in Transistor?
« Reply #4 on: March 19, 2016, 01:11:44 am »
Vceo is the maximum Voltage the transistor can withstand on its collector measured relative to its emitter with the base open circuit.

Likewise:
Vcbo is the maximum Voltage the transistor can withstand on its collector measured relative to its base with the emitter open circuit.
Vbeo is the maximum Voltage the transistor can withstand on its base measured relative to its emitter with the collector open circuit.

How can I calculate the V__o? Thank you.
As Ian.M has said - you don't calculate these.  The manufacturer designs and tests the device to provide you with the information via datasheets.  They GIVE you these numbers (and a whole lot more) for you to use in designing your own circuits.
« Last Edit: March 19, 2016, 01:14:24 am by Brumby »

#### Shock

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##### Re: What is the meaning of Vceo, Vcbo and Vebo in Transistor?
« Reply #5 on: March 19, 2016, 04:47:21 pm »
Multimeters: Fluke 87V, 117, 27/FM
Oscilloscopes: Rigol DS1054Z, Phillips PM3065

#### Walt Peter

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##### Re: What is the meaning of Vceo, Vcbo and Vebo in Transistor?
« Reply #6 on: March 19, 2016, 05:25:43 pm »
How can I know does my circuit exceeded or lower than the "limit"? Thank you very much once again.
On my case, I used 9 volts at Base and Collector respectively. Why the transistor S2013 will dead? Thank you.
« Last Edit: March 19, 2016, 05:40:46 pm by Walt Peter »

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