crystal oscillator discreet pierce oscillator

Although there are many different configurations for Crystal Oscillators, the most common are the discrete and integrated circuits Pierce and environment RLC Bridge. When needed very good frequency stability and reasonably simple circuits, the discrete Pierce is a good choice. When your main concern is the low cost and
crystal oscillator discreet pierce oscillator - schematic

the ability of a simple digital interface will suffice with a Pierce oscillator using IC. However, to the best frequency stability, the half bridge is the best option RLC. The discrete crystal oscillator Pierce has many advantages. Its operating frequency spans the full range of basic glass (from 1 kHz to about 30 MHz). Uses simple circuits that require relatively few components (most frequently versions require only one transistor half). The Pierce oscillator design develops high power output signal while dissipating little power in the same crystal. Finally, the stability of frequency in the short term Pierce crystal oscillator is excellent (this is because in the input circuit of load Q is nearly as high as the internal Q of the crystal). The figure shows a circuit for a discrete Pierce oscillator 1 MHz Q1 provides all the necessary gain self oscillations to occur. R1 and C1 provide a phase delay of 65 ° to the feedback signal. The impedance of the crystal is basically a small resistive inductive component. This impedance reactor combined with C2 provides additional 115 ° phase lag. Transistor inverts the signal (180 ° phase shift), by providing 360 ° required for total phase change to the circuit. Because the load is mainly non resistive glass (mostly the series combination of C1 and C2), this type of oscillator provides very good frequency stability in the short term.

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