Electronically Controllable Colpitts Oscillator with Amplitude Controllability Using Commercially Available ICs

Abstract

This paper proposes a sinusoidal oscillator realized from the LC Colpitts circuit configuration. For this purpose, the commercially available IC, LT1228 is chosen as active element. The current amplifier and grounded inductance simulator with electronic controllable gain and inductance value are respectively used to drive the oscillation condition and the oscillation frequency. These sub-circuits replace the conventional bipolar transistor-based current amplifier and wire coil inductor. Significant features of the proposed Colpitts oscillator include electronic and independent adjustment of oscillation frequency and condition, amplitude controllability of the sinusoidal waveform, and the absence of a wire coil inductor. The proposed oscillator has been tested through an experimental setup using an off-the-shelf IC, LT1228, to verify the theoretical analysis.