A programmable active-R sine wave oscillator with microprocessor control

The design and analysis of a simple active-R oscillator based on a two-pole operational amplifier model are described. The oscillator is tunable by one resistor over a fairly wide range at low sensitivities. A digitally programmable oscillator was derived by replacing the tuner resistor with an array of switched binary weighted resistors. The CMOS switches were activated and controlled by a SDA-UNI-01 microcomputer system based on the 8085 microprocessor. The performance of the programmable oscillator and its extension as a switched frequency-shift-keyed wave generator were verified.<
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