Output Resistance of Widlar Current Source Solution

STEP 0: Pre-Calculation Summary
Formula Used
Output Resistance of Widlar Current Source = (1+Transconductance)*((1/Emitter Resistance)+(1/Small-Signal Input Resistance b/w Base-Emitter))*Finite Output Resistance
Rwcs = (1+gm)*((1/Re)+(1/Rsbe))*Rfo
This formula uses 5 Variables
Variables Used
Output Resistance of Widlar Current Source - (Measured in Ohm) - Output Resistance of Widlar Current Source is the calculated resistance value obtained by adding the inverese values of individual resistors values.
Transconductance - (Measured in Siemens) - Transconductance is the change in the drain current divided by the small change in the gate/source voltage with a constant drain/source voltage.
Emitter Resistance - (Measured in Ohm) - Emitter Resistance is the emitter-degeneration resistance of the emitter-base junction diode of a transistor.
Small-Signal Input Resistance b/w Base-Emitter - (Measured in Ohm) - Small-Signal input resistance b/w base-emitter is the opposition offered to the current passing through the base-emitter region.
Finite Output Resistance - (Measured in Ohm) - The finite output resistance is the measure of the opposition to current flow, both static and dynamic, into the load network being connected that is internal to the electrical source.
STEP 1: Convert Input(s) to Base Unit
Transconductance: 0.25 Siemens --> 0.25 Siemens No Conversion Required
Emitter Resistance: 0.909 Kilohm --> 909 Ohm (Check conversion here)
Small-Signal Input Resistance b/w Base-Emitter: 20 Kilohm --> 20000 Ohm (Check conversion here)
Finite Output Resistance: 1.45 Kilohm --> 1450 Ohm (Check conversion here)
STEP 2: Evaluate Formula
Substituting Input Values in Formula
Rwcs = (1+gm)*((1/Re)+(1/Rsbe))*Rfo --> (1+0.25)*((1/909)+(1/20000))*1450
Evaluating ... ...
Rwcs = 2.08457439493949
STEP 3: Convert Result to Output's Unit
2.08457439493949 Ohm -->0.00208457439493949 Kilohm (Check conversion here)
FINAL ANSWER
0.00208457439493949 0.002085 Kilohm <-- Output Resistance of Widlar Current Source
(Calculation completed in 00.020 seconds)

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10+ IC Amplifiers Calculators

Output Resistance of Widlar Current Source
Go Output Resistance of Widlar Current Source = (1+Transconductance)*((1/Emitter Resistance)+(1/Small-Signal Input Resistance b/w Base-Emitter))*Finite Output Resistance
Emitter Resistance in Widlar Current Source
Go Emitter Resistance = (Threshold Voltage/Output Current)*log10(Reference Current/Output Current)
Output Current
Go Output Current given Reference Current = Reference Current*(Current in Transistor 2/Current in Transistor 1)
Output Resistance of Wilson MOS Mirror
Go Output Resistance = (Transconductance 3*Finite Output Resistance 3)*Finite Output Resistance 2
Output Resistance of Wilson Current Mirror
Go Output Resistance of Wilson Current Mirror = (Transistor Current Gain 1*Finite Output Resistance 3)/2
Reference Current of IC Amplifier
Go Reference Current = Output Current*(Aspect Ratio/Aspect Ratio 1)
Output Current of Wilson Current Mirror
Go Output Current = Reference Current*(1/(1+(2/Transistor Current Gain^2)))
Finite Output Resistance of IC Amplifier
Go Finite Output Resistance = Change in Output Voltage/Change in Current
Reference Current of Wilson Current Mirror
Go Reference Current = (1+2/Transistor Current Gain^2)*Output Current
Intrinsic Gain of IC Amplifier
Go Intrinsic Gain = 2*Early Voltage/Overdrive Voltage

Output Resistance of Widlar Current Source Formula

Output Resistance of Widlar Current Source = (1+Transconductance)*((1/Emitter Resistance)+(1/Small-Signal Input Resistance b/w Base-Emitter))*Finite Output Resistance
Rwcs = (1+gm)*((1/Re)+(1/Rsbe))*Rfo

What is a Widlar Current Source?

A Widlar current source is a modification of the basic two-transistor current mirror that incorporates an emitter degeneration resistor for only the output transistor, enabling the current source to generate low currents using only moderate resistor values.

How to Calculate Output Resistance of Widlar Current Source?

Output Resistance of Widlar Current Source calculator uses Output Resistance of Widlar Current Source = (1+Transconductance)*((1/Emitter Resistance)+(1/Small-Signal Input Resistance b/w Base-Emitter))*Finite Output Resistance to calculate the Output Resistance of Widlar Current Source, The output resistance of Widlar Current Source formula is defined as the opposition offered to the flow of the current in the Widlar Current Source. Output Resistance of Widlar Current Source is denoted by Rwcs symbol.

How to calculate Output Resistance of Widlar Current Source using this online calculator? To use this online calculator for Output Resistance of Widlar Current Source, enter Transconductance (gm), Emitter Resistance (Re), Small-Signal Input Resistance b/w Base-Emitter (Rsbe) & Finite Output Resistance (Rfo) and hit the calculate button. Here is how the Output Resistance of Widlar Current Source calculation can be explained with given input values -> 2.1E-6 = (1+0.25)*((1/909)+(1/20000))*1450.

FAQ

What is Output Resistance of Widlar Current Source?
The output resistance of Widlar Current Source formula is defined as the opposition offered to the flow of the current in the Widlar Current Source and is represented as Rwcs = (1+gm)*((1/Re)+(1/Rsbe))*Rfo or Output Resistance of Widlar Current Source = (1+Transconductance)*((1/Emitter Resistance)+(1/Small-Signal Input Resistance b/w Base-Emitter))*Finite Output Resistance. Transconductance is the change in the drain current divided by the small change in the gate/source voltage with a constant drain/source voltage, Emitter Resistance is the emitter-degeneration resistance of the emitter-base junction diode of a transistor, Small-Signal input resistance b/w base-emitter is the opposition offered to the current passing through the base-emitter region & The finite output resistance is the measure of the opposition to current flow, both static and dynamic, into the load network being connected that is internal to the electrical source.
How to calculate Output Resistance of Widlar Current Source?
The output resistance of Widlar Current Source formula is defined as the opposition offered to the flow of the current in the Widlar Current Source is calculated using Output Resistance of Widlar Current Source = (1+Transconductance)*((1/Emitter Resistance)+(1/Small-Signal Input Resistance b/w Base-Emitter))*Finite Output Resistance. To calculate Output Resistance of Widlar Current Source, you need Transconductance (gm), Emitter Resistance (Re), Small-Signal Input Resistance b/w Base-Emitter (Rsbe) & Finite Output Resistance (Rfo). With our tool, you need to enter the respective value for Transconductance, Emitter Resistance, Small-Signal Input Resistance b/w Base-Emitter & Finite Output Resistance 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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