Amplifier Design and Modeling

Doug Bouler: CURENT REU

Dr. Daniel Costinett: Mentor

Final CURENT Presentation

7/18/2014

Knoxville, TN

Outline

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1. Research goals2. Process

• Class A Amplification• Class AB Amplification• Model and Transfer Characteristic

3. Results 4. Future Work

Research Goals

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• Design and Model a Class AB amplifier using LT-spice and MATLAB

• Make Class AB amplifier capable of amplifying an audio signal

• Test Magnitude and Phase Response

Class A Amplifiers

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Vgate-source = Vrail x (R2 / R1 + R2)

R1/R2 = (Vrail - Vgs ) / Vgs

Input Signal

Voltage Rail

Output Signal

Vgs

Class A Amplifiers

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Data of DC Analysis from 0V to 3V DC to find midpoint of slope

Optimal Vgs

Input Signal

Output Signal

VGS

VDD

Cutoff Region

Class A Amplifiers

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Vgate-source = Vrail x (R2 / R1 + R2)

Vgate-source = Vrail x (R2 / R1 + R2)

Voltage Loss

Class AB Amplifiers

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Class A

Class AB

Matching Transistors

Class AB Amplifiers

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Matching Transistors

Class B Output Stage

Class AB Output Stage

Modeling Process

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Collect Data from Output of Amplifier Stage

Normalize Data in MATLAB

Graph Input and Output

Voltage Response

Develop Transfer

Characteristic

Model Audio Response

Results

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This figure shows the frequencies at which the magnitude of the output signal begins to attenuate

4000 Hz

Results

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• η = Pout / Pin = 44.64%

• A = Vout / Vin = 40 V/V

Future Work

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• Research methods of Wireless Power Transfer (WPT)

• Research Specific Absorption Rates (SAR) of WPT for Biomedical applications

• Use knowledge gained from this project to begin designing devices capable of WPT

“This work was supported primarily by the Engineering Research Center 

Program of the National Science Foundation and the Department of Energy 

under NSF Award Number EEC-1041877 and the CURENT Industry Partnership 

Program. "

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Acknowledgements