In which oscillator circuit would you find a quartz crystal?

In a Pierce oscillator circuit, a quartz crystal is used as a frequency-determining element. The Pierce oscillator is a type of crystal oscillator that utilizes the properties of the crystal to provide high stability and precision in frequency generation. The specific advantage of incorporating a quartz crystal in this type of oscillator lies in its ability to maintain a consistent frequency due to the high Q-factor (quality factor) of quartz, which minimizes phase noise and ensures a stable output frequency.

The configuration of the Pierce oscillator typically includes an inverter (or an op-amp configured as a non-inverting amplifier) along with the quartz crystal connected between the output and the input. This feedback method reinforces oscillations at the crystal's resonant frequency, allowing for efficient frequency generation. Other oscillator circuits like the astable, monostable, and Colpitts do not inherently require quartz crystals for their operation and instead rely on different types of components (like capacitors and inductors) to set their oscillation frequencies, making them less stable than a Pierce oscillator that incorporates a quartz crystal.