Common-Base Current Gain Calculator

✖Common emitter current gain is influenced by 2 factors: width of base region W, and relative dopings of base region and emitter region. Its range varies from 50-200.ⓘ Common Emitter Current Gain [β]

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✖Common-base current gain α is related to β common-emitter current gain and its value is less than 1 because collector current is always less than emitter current due to recombination of electrons.ⓘ Common-Base Current Gain [α]

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Formula

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Common-Base Current Gain

Formula

`"α" = "β"/("β"+1)`

Example

`"0.984848"="65"/("65"+1)`

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Common-Base Current Gain Solution

STEP 0: Pre-Calculation Summary

Formula Used

Common-Base Current Gain = Common Emitter Current Gain/(Common Emitter Current Gain+1)
α = β/(β+1)
This formula uses 2 Variables

Variables Used

Common-Base Current Gain - Common-base current gain α is related to β common-emitter current gain and its value is less than 1 because collector current is always less than emitter current due to recombination of electrons.
Common Emitter Current Gain - Common emitter current gain is influenced by 2 factors: width of base region W, and relative dopings of base region and emitter region. Its range varies from 50-200.

STEP 1: Convert Input(s) to Base Unit

Common Emitter Current Gain: 65 --> No Conversion Required

STEP 2: Evaluate Formula

Substituting Input Values in Formula

α = β/(β+1) --> 65/(65+1)

Evaluating ... ...

α = 0.984848484848485

STEP 3: Convert Result to Output's Unit

0.984848484848485 --> No Conversion Required

FINAL ANSWER

0.984848484848485 ≈ 0.984848 <-- Common-Base Current Gain

(Calculation completed in 00.004 seconds)

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Credits

Created by Payal Priya

Birsa Institute of Technology (BIT), Sindri

Payal Priya has created this Calculator and 600+ more calculators!

Verified by Urvi Rathod

Vishwakarma Government Engineering College (VGEC), Ahmedabad

Urvi Rathod has verified this Calculator and 1900+ more calculators!

< 16 Amplification Factor/Gain Calculators

Amplification Factor of BJT

Go BJT Amplification Factor = (Collector Current/Threshold Voltage)*((Positive DC Voltage+Collector-Emitter Voltage)/Collector Current)

Overall Voltage Gain of Amplifier when Load Resistance is Connected to Output

Go Voltage Gain = Common-Base Current Gain*(1/Collector Resistance+1/Load Resistance)^-1/(Signal Resistance+Emitter Resistance)

Overall Voltage Gain of Buffer Amplifier given Load Resistance

Go Voltage Gain = Load Resistance/(Load Resistance+Emitter Resistance+Signal Resistance/(Common Emitter Current Gain+1))

Overall Voltage Gain given Load Resistance of BJT

Go Voltage Gain = -Transconductance*((Collector Resistance*Load Resistance)/(Collector Resistance+Load Resistance))

Common Mode Gain of BJT

Go Common Mode Gain = -(Collector Resistance/(2*Output Resistance))*(Change in Collector Resistance/Collector Resistance)

Total Power Dissipated in BJT

Go Power = Collector-Emitter Voltage*Collector Current+Base-Emitter Voltage*Base Current

Voltage Gain given all Voltages

Go Voltage Gain = -(Supply Voltage-Collector-Emitter Voltage)/Thermal Voltage

Voltage Gain given Collector Current

Go Voltage Gain = -(Collector Current/Thermal Voltage)*Collector Resistance

Total Power Supplied in BJT

Go Power = Supply Voltage*(Collector Current+Input Current)

Common-Base Current Gain

Go Common-Base Current Gain = Common Emitter Current Gain/(Common Emitter Current Gain+1)

Common-Emitter Current Gain using Common-Base Current Gain

Go Common Emitter Current Gain = Common-Base Current Gain/(1-Common-Base Current Gain)

Open Circuit Voltage Gain given Open Circuit Transresistance

Go Open Circuit Voltage Gain = Open Circuit Transresistance/Input Resistance

Forced Common-Emitter Current Gain

Go Forced Common-Emitter Current Gain = Collector Current/Base Current

Voltage Gain given Transconductance and Collector Resistance

Go Voltage Gain = -Transconductance*Collector Resistance

Intrinsic Gain of BJT

Go Intrinsic Gain = Early Voltage/Thermal Voltage

Short-Circuit Current Gain

Go Current Gain = Output Current/Input Current

< 20 BJT Circuit Calculators

Transition Frequency of BJT

Go Transition Frequency = Transconductance/(2*pi*(Emitter-Base Capacitance+Collector-Base Junction Capacitance))

Base Current of PNP Transistor using Saturation Current

Go Base Current = (Saturation Current/Common Emitter Current Gain)*e^(Base-Emitter Voltage/Thermal Voltage)

Total Power Dissipated in BJT

Go Power = Collector-Emitter Voltage*Collector Current+Base-Emitter Voltage*Base Current

Unity-Gain Bandwidth of BJT

Go Unity-Gain Bandwidth = Transconductance/(Emitter-Base Capacitance+Collector-Base Junction Capacitance)

Reference Current of BJT Mirror

Go Reference Current = Collector Current+(2*Collector Current)/Common Emitter Current Gain

Common Mode Rejection Ratio

Go Common Mode Rejection Ratio = 20*log10(Differential Mode Gain/Common Mode Gain)

Output Resistance of BJT

Go Resistance = (Supply Voltage+Collector-Emitter Voltage)/Collector Current

Thermal Equilibrium Concentration of Minority Charge Carrier

Go Thermal Equilibrium Concentration = ((Intrinsic Carrier Density)^2)/Doping Concentration of Base

Output Voltage of BJT Amplifier

Go Output Voltage = Supply Voltage-Drain Current*Load Resistance

Total Power Supplied in BJT

Go Power = Supply Voltage*(Collector Current+Input Current)

Common-Base Current Gain

Go Common-Base Current Gain = Common Emitter Current Gain/(Common Emitter Current Gain+1)

Collector to Emitter Voltage at Saturation

Go Collector-Emitter Voltage = Base-Emitter Voltage-Base-Collector Voltage

Base Current of PNP Transistor given Emitter Current

Go Base Current = Emitter Current/(Common Emitter Current Gain+1)

Base Current of PNP Transistor using Collector Current

Go Base Current = Collector Current/Common Emitter Current Gain

Collector Current using Emitter Current

Go Collector Current = Common-Base Current Gain*Emitter Current

Base Current of PNP Transistor using Common-Base Current Gain

Go Base Current = (1-Common-Base Current Gain)*Emitter Current

Collector Current of BJT

Go Collector Current = Emitter Current-Base Current

Emitter Current of BJT

Go Emitter Current = Collector Current+Base Current

Short-Circuit Transconductance

Go Transconductance = Output Current/Input Voltage

Intrinsic Gain of BJT

Go Intrinsic Gain = Early Voltage/Thermal Voltage

Common-Base Current Gain Formula

Common-Base Current Gain = Common Emitter Current Gain/(Common Emitter Current Gain+1)
α = β/(β+1)

On what factors constant of a transistor depends?

Small changes in α correspond to very large changes in β. This mathematical
observation manifests itself physically, with the result that transistors of the same type may
have widely different values of β. For reasons that will become apparent later, α is called the
common-base current gain.

How to Calculate Common-Base Current Gain?

Common-Base Current Gain calculator uses Common-Base Current Gain = Common Emitter Current Gain/(Common Emitter Current Gain+1) to calculate the Common-Base Current Gain, The common-base current gain of a transistor for a particular transistor that is less than or close to the unity. . For instance, if β =100, then α ≅0.99. Common-Base Current Gain is denoted by α symbol.

How to calculate Common-Base Current Gain using this online calculator? To use this online calculator for Common-Base Current Gain, enter Common Emitter Current Gain (β) and hit the calculate button. Here is how the Common-Base Current Gain calculation can be explained with given input values -> 0.984848 = 65/(65+1).

FAQ

What is Common-Base Current Gain?

The common-base current gain of a transistor for a particular transistor that is less than or close to the unity. . For instance, if β =100, then α ≅0.99 and is represented as α = β/(β+1) or Common-Base Current Gain = Common Emitter Current Gain/(Common Emitter Current Gain+1). Common emitter current gain is influenced by 2 factors: width of base region W, and relative dopings of base region and emitter region. Its range varies from 50-200.

How to calculate Common-Base Current Gain?

The common-base current gain of a transistor for a particular transistor that is less than or close to the unity. . For instance, if β =100, then α ≅0.99 is calculated using Common-Base Current Gain = Common Emitter Current Gain/(Common Emitter Current Gain+1). To calculate Common-Base Current Gain, you need Common Emitter Current Gain (β). With our tool, you need to enter the respective value for Common Emitter Current Gain and hit the calculate button. You can also select the units (if any) for Input(s) and the Output as well.

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