Input Resistance of Emitter Follower Calculator

✖Signal Resistance in base is the current flowing through the base at any moment.ⓘ Signal Resistance in Base [R_sb]			+10% -10%
✖Base resistance is a measure of the opposition to current flow in an electrical circuit.ⓘ Base Resistance [R_b]			+10% -10%

✖Input resistance 2 is the opposition that an electrical component or circuit presents to the flow of electrical current when a voltage is applied to it.ⓘ Input Resistance of Emitter Follower [R_in]

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Formula

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Input Resistance of Emitter Follower

Formula

`"R"_{"in"} = 1/(1/"R"_{"sb"}+1/"R"_{"b"})`

Example

`"0.306426kΩ"=1/(1/"0.41kΩ"+1/"1.213kΩ")`

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Input Resistance of Emitter Follower Solution

STEP 0: Pre-Calculation Summary

Formula Used

Input Resistance = 1/(1/Signal Resistance in Base+1/Base Resistance)
R_in = 1/(1/R_sb+1/R_b)
This formula uses 3 Variables

Variables Used

Input Resistance - (Measured in Ohm) - Input resistance 2 is the opposition that an electrical component or circuit presents to the flow of electrical current when a voltage is applied to it.
Signal Resistance in Base - (Measured in Ohm) - Signal Resistance in base is the current flowing through the base at any moment.
Base Resistance - (Measured in Ohm) - Base resistance is a measure of the opposition to current flow in an electrical circuit.

STEP 1: Convert Input(s) to Base Unit

Signal Resistance in Base: 0.41 Kilohm --> 410 Ohm (Check conversion here)
Base Resistance: 1.213 Kilohm --> 1213 Ohm (Check conversion here)

STEP 2: Evaluate Formula

Substituting Input Values in Formula

R_in = 1/(1/R_sb+1/R_b) --> 1/(1/410+1/1213)

Evaluating ... ...

R_in = 306.426370918053

STEP 3: Convert Result to Output's Unit

306.426370918053 Ohm -->0.306426370918053 Kilohm (Check conversion here)

FINAL ANSWER

0.306426370918053 ≈ 0.306426 Kilohm <-- Input Resistance

(Calculation completed in 00.004 seconds)

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Created by Payal Priya

Birsa Institute of Technology (BIT), Sindri

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Vishwakarma Government Engineering College (VGEC), Ahmedabad

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< 10+ Emitter Follower Calculators

Output Resistance of Emitter Follower

Go Finite Resistance = (1/Load Resistance+1/Small Signal Voltage+1/Emitter Resistance)+(1/Base Impedance+1/Signal Resistance)/(Collector Base Current Gain+1)

Collector Current in Active Region when Transistor Acts as Amplifier

Go Collector Current = Saturation Current*e^(Voltage across Base Emitter Junction/Threshold Voltage)

Saturation Current of Emitter Follower

Go Saturation Current = Collector Current/e^(Voltage across Base Emitter Junction/Threshold Voltage)

Input Resistance of Emitter Follower

Go Input Resistance = 1/(1/Signal Resistance in Base+1/Base Resistance)

Base Resistance across Emitter follower Junction

Go Base Resistance = High Frequency Constant*Emitter Resistance

Total Emitter Resistance of Emitter Follower

Go Emitter Resistance = Base Resistance/High Frequency Constant

Output Resistance of Transistor at Intrinsic Gain

Go Finite Output Resistance = Early Voltage/Collector Current

Collector Current of Emitter Follower Transistor

Go Collector Current = Early Voltage/Finite Output Resistance

Input Resistance of Transistor Amplifier

Go Input Resistance = Amplifier Input/Input Current

Input Voltage of Emitter Follower

Go Emitter Voltage = Base Voltage-0.7

< 15 Multi Stage Transistor Amplifiers Calculators

Open Circuit Bipolar Cascode Voltage Gain

Go Bipolar Cascode Voltage Gain = -MOSFET Primary Transconductance*(MOSFET Secondary Transconductance*Finite Output Resistance)*(1/Finite Output Resistance of Transistor 1+1/Small Signal Input Resistance)^-1

Output Resistance of Emitter Follower

Go Finite Resistance = (1/Load Resistance+1/Small Signal Voltage+1/Emitter Resistance)+(1/Base Impedance+1/Signal Resistance)/(Collector Base Current Gain+1)

Drain Resistance of Cascode Amplifier

Go Drain Resistance = (Output Voltage Gain/(MOSFET Primary Transconductance^2*Finite Output Resistance))

Output voltage gain of MOS Cascode Amplifier

Go Output Voltage Gain = -MOSFET Primary Transconductance^2*Finite Output Resistance*Drain Resistance

Collector Current in Active Region when Transistor Acts as Amplifier

Go Collector Current = Saturation Current*e^(Voltage across Base Emitter Junction/Threshold Voltage)

Saturation Current of Emitter Follower

Go Saturation Current = Collector Current/e^(Voltage across Base Emitter Junction/Threshold Voltage)

Equivalent Resistance of Cascode Amplifier

Go Resistance between Drain and Ground = (1/Finite Output Resistance of Transistor 1+1/Input Resistance)^-1

Negative Voltage Gain of Cascode Amplifier

Go Negative Voltage Gain = -(MOSFET Primary Transconductance*Resistance between Drain and Ground)

Input Resistance of Emitter Follower

Go Input Resistance = 1/(1/Signal Resistance in Base+1/Base Resistance)

Base Resistance across Emitter follower Junction

Go Base Resistance = High Frequency Constant*Emitter Resistance

Total Emitter Resistance of Emitter Follower

Go Emitter Resistance = Base Resistance/High Frequency Constant

Output Resistance of Transistor at Intrinsic Gain

Go Finite Output Resistance = Early Voltage/Collector Current

Collector Current of Emitter Follower Transistor

Go Collector Current = Early Voltage/Finite Output Resistance

Input Resistance of Transistor Amplifier

Go Input Resistance = Amplifier Input/Input Current

Input Voltage of Emitter Follower

Go Emitter Voltage = Base Voltage-0.7

Input Resistance of Emitter Follower Formula

Input Resistance = 1/(1/Signal Resistance in Base+1/Base Resistance)
R_in = 1/(1/R_sb+1/R_b)

What is meant by emitter follower?

Emitter follower is a case of the negative current feedback circuit. This is mostly used as a last-stage amplifier in signal generator circuits. The important features of Emitter Follower are − It has high input impedance. It has a low output impedance.

How to Calculate Input Resistance of Emitter Follower?

Input Resistance of Emitter Follower calculator uses Input Resistance = 1/(1/Signal Resistance in Base+1/Base Resistance) to calculate the Input Resistance, The input resistance of emitter follower formula is defined as opposition offered to flow of current in base region of electrical circuit. Input Resistance is denoted by R_in symbol.

How to calculate Input Resistance of Emitter Follower using this online calculator? To use this online calculator for Input Resistance of Emitter Follower, enter Signal Resistance in Base (R_sb) & Base Resistance (R_b) and hit the calculate button. Here is how the Input Resistance of Emitter Follower calculation can be explained with given input values -> 0.000939 = 1/(1/410+1/1213).

FAQ

What is Input Resistance of Emitter Follower?

The input resistance of emitter follower formula is defined as opposition offered to flow of current in base region of electrical circuit and is represented as R_in = 1/(1/R_sb+1/R_b) or Input Resistance = 1/(1/Signal Resistance in Base+1/Base Resistance). Signal Resistance in base is the current flowing through the base at any moment & Base resistance is a measure of the opposition to current flow in an electrical circuit.

How to calculate Input Resistance of Emitter Follower?

The input resistance of emitter follower formula is defined as opposition offered to flow of current in base region of electrical circuit is calculated using Input Resistance = 1/(1/Signal Resistance in Base+1/Base Resistance). To calculate Input Resistance of Emitter Follower, you need Signal Resistance in Base (R_sb) & Base Resistance (R_b). With our tool, you need to enter the respective value for Signal Resistance in Base & Base Resistance and hit the calculate button. You can also select the units (if any) for Input(s) and the Output as well.

How many ways are there to calculate Input Resistance?

In this formula, Input Resistance uses Signal Resistance in Base & Base Resistance. We can use 2 other way(s) to calculate the same, which is/are as follows -

Input Resistance = Amplifier Input/Input Current
Input Resistance = Amplifier Input/Input Current

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