Input Resistance with Feedback Current Amplifier Calculator

✖The Input Resistance is the resistance seen by the current source or voltage source which drives the circuit.ⓘ Input Resistance [R_in]			+10% -10%
✖The loop gain is calculated by imagining the feedback loop is broken at some point and calculating the net gain if a signal is applied.ⓘ Loop Gain [Aβ]			+10% -10%

✖The input resistance with feedback of a feedback amplifier is equal to the source impedance for which loop gain would drop to unity.ⓘ Input Resistance with Feedback Current Amplifier [R_inf]

⎘ Copy

👎

Formula

✖

Input Resistance with Feedback Current Amplifier

Formula

`"R"_{"inf"} = "R"_{"in"}/(1+"Aβ")`

Example

`"6.944444kΩ"="25kΩ"/(1+"2.6")`

Calculator

LaTeX

Reset

👍

Download Feedback Amplifiers Formula PDF

Input Resistance with Feedback Current Amplifier Solution

STEP 0: Pre-Calculation Summary

Formula Used

Input Resistance with Feedback = Input Resistance/(1+Loop Gain)
R_inf = R_in/(1+Aβ)
This formula uses 3 Variables

Variables Used

Input Resistance with Feedback - (Measured in Ohm) - The input resistance with feedback of a feedback amplifier is equal to the source impedance for which loop gain would drop to unity.
Input Resistance - (Measured in Ohm) - The Input Resistance is the resistance seen by the current source or voltage source which drives the circuit.
Loop Gain - The loop gain is calculated by imagining the feedback loop is broken at some point and calculating the net gain if a signal is applied.

STEP 1: Convert Input(s) to Base Unit

Input Resistance: 25 Kilohm --> 25000 Ohm (Check conversion here)
Loop Gain: 2.6 --> No Conversion Required

STEP 2: Evaluate Formula

Substituting Input Values in Formula

R_inf = R_in/(1+Aβ) --> 25000/(1+2.6)

Evaluating ... ...

R_inf = 6944.44444444444

STEP 3: Convert Result to Output's Unit

6944.44444444444 Ohm -->6.94444444444444 Kilohm (Check conversion here)

FINAL ANSWER

6.94444444444444 ≈ 6.944444 Kilohm <-- Input Resistance with Feedback

(Calculation completed in 00.004 seconds)

You are here -

Home » Engineering » Electronics » Amplifiers » Feedback Amplifiers » Current Feedback Amplifiers » Input Resistance with Feedback Current Amplifier

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!

< 2 Current Feedback Amplifiers Calculators

Output Resistance with Feedback Current Amplifier

Go Output Resistance of Current Amplifier = Amount of Feedback*Output Resistance

Input Resistance with Feedback Current Amplifier

Go Input Resistance with Feedback = Input Resistance/(1+Loop Gain)

< 15 Negative Feedback Amplifiers Calculators

Feedback Signal

Go Feedback Signal = ((Open Loop Gain of an Operational Amplifier*Feedback Factor)/(1+(Open Loop Gain of an Operational Amplifier*Feedback Factor)))*Source Signal

Error Signal

Go Error Signal = Source Signal/(1+(Open Loop Gain of an Operational Amplifier*Feedback Factor))

Gain at Mid and High Frequencies

Go Gain Factor = Mid Band Gain/(1+(Complex Frequency Variable/Upper 3-dB Frequency))

Signal-to-Interference Ratio at Output

Go Signal to Interference Ratio = (Source Voltage/Voltage Interference)*Gain Factor

Lower 3-DB Frequency in Bandwidth Extension

Go Lower 3-dB Frequency = 3-dB Frequency/(1+(Mid Band Gain*Feedback Factor))

Upper 3-DB Frequency of Feedback Amplifier

Go Upper 3-dB Frequency = 3-dB Frequency*(1+Mid Band Gain*Feedback Factor)

Output Current of Feedback Voltage Amplifier Given Loop Gain

Go Output Current = (1+Loop Gain)*Output Voltage/Output Resistance

Gain with Feedback of Feedback Amplifier

Go Gain with Feedback = (Open Loop Gain of an Operational Amplifier)/Amount of Feedback

Output Signal in Feedback Amplifier

Go Signal Output = Open Loop Gain of an Operational Amplifier*Input Signal Feedback

Output Resistance with Feedback Current Amplifier

Go Output Resistance of Current Amplifier = Amount of Feedback*Output Resistance

Output Resistance with Feedback Voltage Amplifier

Go Output Resistance of Voltage Amplifier = Output Resistance/(1+Loop Gain)

Input Resistance with Feedback Current Amplifier

Go Input Resistance with Feedback = Input Resistance/(1+Loop Gain)

Closed-Loop Gain as Function of Ideal Value

Go Closed-Loop Gain = (1/Feedback Factor)*(1/(1+(1/Loop Gain)))

Feedback Factor of Feedback Amplifier

Go Feedback Factor = Input Signal Feedback/Signal Output

Amount of Feedback Given Loop Gain

Go Amount of Feedback = 1+Loop Gain

Input Resistance with Feedback Current Amplifier Formula

Input Resistance with Feedback = Input Resistance/(1+Loop Gain)
R_inf = R_in/(1+Aβ)

Why are current feedback amplifiers used?

With a current-feedback amplifier, the low-impedance input allows higher transient currents to flow into the amplifier as needed. The internal current mirrors convey this input current to the compensation node, allowing fast charging and discharging-theoretically, in proportion to input step size.

How to Calculate Input Resistance with Feedback Current Amplifier?

Input Resistance with Feedback Current Amplifier calculator uses Input Resistance with Feedback = Input Resistance/(1+Loop Gain) to calculate the Input Resistance with Feedback, Input Resistance with Feedback Current Amplifier is defined as the resistance seen by the current source or voltage source which drives the circuit. Input Resistance with Feedback is denoted by R_inf symbol.

How to calculate Input Resistance with Feedback Current Amplifier using this online calculator? To use this online calculator for Input Resistance with Feedback Current Amplifier, enter Input Resistance (R_in) & Loop Gain (Aβ) and hit the calculate button. Here is how the Input Resistance with Feedback Current Amplifier calculation can be explained with given input values -> 0.006944 = 25000/(1+2.6).

FAQ

What is Input Resistance with Feedback Current Amplifier?

Input Resistance with Feedback Current Amplifier is defined as the resistance seen by the current source or voltage source which drives the circuit and is represented as R_inf = R_in/(1+Aβ) or Input Resistance with Feedback = Input Resistance/(1+Loop Gain). The Input Resistance is the resistance seen by the current source or voltage source which drives the circuit & The loop gain is calculated by imagining the feedback loop is broken at some point and calculating the net gain if a signal is applied.

How to calculate Input Resistance with Feedback Current Amplifier?

Input Resistance with Feedback Current Amplifier is defined as the resistance seen by the current source or voltage source which drives the circuit is calculated using Input Resistance with Feedback = Input Resistance/(1+Loop Gain). To calculate Input Resistance with Feedback Current Amplifier, you need Input Resistance (R_in) & Loop Gain (Aβ). With our tool, you need to enter the respective value for Input Resistance & Loop Gain and hit the calculate button. You can also select the units (if any) for Input(s) and the Output as well.

Home

FREE PDFs

🔍 Search