Quartz crystal sine wave oscillator circuit

The image depicts a sine wave oscillator that consists of a quartz crystal (SJT) and gate A of the hex inverter IC CD4069. Compared to a standard RC phase-shift oscillator, the frequency stability of a crystal oscillator can achieve 10^-5 or higher. This level of stability (the RC phase-shift oscillator can only reach about 10^-2) cannot be matched by the RC phase-shift oscillator. The CMOS NAND gate and the negative feedback bias resistor R1 create the inverting amplifier circuit. The quartz crystal SJT, along with capacitors C1 and C2, forms the positive feedback branch of the oscillator circuit.

The sine wave oscillator circuit utilizes the properties of the quartz crystal to achieve high frequency stability, which is essential for various applications requiring precise timing signals. The CD4069 hex inverter IC is employed to provide the necessary gain and phase inversion. The oscillator's design incorporates a combination of the quartz crystal, which serves as a frequency-determining element, and the feedback network formed by R1 and the capacitors C1 and C2.

In operation, the quartz crystal SJT resonates at its fundamental frequency, establishing a stable oscillation. The negative feedback provided by resistor R1 ensures that the output of the inverter remains within the linear operating region, preventing distortion of the sine wave. The capacitors C1 and C2 are chosen to create the appropriate phase shift required for the oscillator to sustain oscillations. The combination of these components allows the circuit to produce a clean sine wave output with minimal frequency drift.

Overall, this sine wave oscillator circuit is a reliable solution for generating high-quality sine wave signals, making it suitable for applications in communication systems, signal processing, and other electronic devices requiring stable frequency sources.The picture shows the sine wave oscillator which is composed of the quartz crystal SJT and the gate A of the hex inverter IC CD4069 Compared with the ordinary RC phase-shift oscillator, the stability of crystal oscillator`s frequency can reach 10-5 or higher. This high index (The stability of the RC phase-shift oscillator`s frequency only can re ach 10-2) can not be reached by the RC phase-shift oscillator. CMOS NAND gate and the negative feedback bias resistor R1 form the inverting amplifier circuit. Quartz crystal SJT, C1 and C1 form the 7c type positive feedback branch. 🔗 External reference