THE DESIGNERS:

Natalie KacikDavid Thomason

Debashree Guruaribam

Monophonic Analog Synthesizer

SPECSFrequency Range = 130.81 Hz 1046.5 HzControl Relation = 1V/Octave

CHOOSING THE BEST WAVEFORMWaveform Frequency content

Single frequency at fundamental

Increasing Frequency Content

The VCO(Voltage-Controlled

Oscillator)

𝑉 𝑜𝑢𝑡=¿+

-

𝐼𝐶=

𝑑𝑉𝑑𝑡 →

𝑑𝑉𝑑𝑡

1Δ𝑉

VCO Design

EC

The Exponential Converter

𝐼 𝑜𝑢𝑡=𝐼𝑏𝑖𝑎𝑠𝑒𝑉 𝑐𝑜𝑛𝑡

𝑉 𝑇𝐼𝑏𝑖𝑎𝑠𝑒

38.46∗𝑘∗𝑉 𝑐𝑜𝑛𝑡=𝐼𝑏𝑖𝑎𝑠2𝑉 𝑐𝑜𝑛𝑡

𝑘≈0.018

VCO PerformanceVcont Output Frequency

0V 103.84 Hz

1V 205.76 Hz

2V 409.83 Hz

3V 501.25 Hz

Voltage-Controlled Filter

Operational Transconductance Amplifier (OTA)

𝐵𝑊 3 𝑑𝐵=𝑘𝑔𝑚

2𝜋𝐶

I out=gm¿

Bandwidth Equation:

OTA Transfer Characteristic Equation:

𝑘=𝑅3

𝑅4+𝑅3

VCF Performance

VCF Output Bode PlotInput Current: 500pAInput Signal: 1mV (-60 dB)

Bandwidth-Current Relation

Attack-Release Envelope and Mixer

Our Amazingly Simple Mixer.

Gain Control Stage Small Signal

Amplification Stage

The Final Output:Filtered Signal mixed with the AR Wave

Putting it all together

Improvements(for the next design cycle)

• Higher frequency range VCO• Use higher order filters (instead of single pole)• ADSR• More effective mixer• Independent biasing circuits

Questions???

Adam Holzman(Musician)