Voltage Controlled Amplitude Sinusoidal Oscillator Using CFOAs

This article presents the design of an oscillator circuit that enables direct control of signal amplitude. The work highlights two key aspects. First, it employs a voltage control technique applied directly to the oscillator circuit, eliminating the need for an external analog signal multiplier. This approach results in a compact, cost-effective design. Second, the circuit is analyzed using the multi-time variables technique approach, which clearly illustrates the relationship between the control voltage and the oscillator’s signal amplitude. The proposed circuit structure consists of two Current Feedback Operational Amplifiers (CFOAs), along with a few resistors and capacitors. Test results from the circuit, built on a versatile prototype board, demonstrate that it generates a sine wave, with amplitude controllable by an external voltage input. The simplicity and the efficiency of this design make it highly suitable for applications in signal processing and communication systems.