Colpitts Crystal Oscillator

We can create Crystal Colpitts oscillator using a parallel mode crystal and a transistor. The circuit shown by the following figure

colpitts xtal oscillator circuit circuit schematic diagram

As an inductance, this circuit uses crystal. The crystal circuit consist of a large value capacitive divider that is  used between gate, a small series capacitor, ground, and source. Component’s values that we choose must produce a highest ratio between C2+C3 and C1. Usually the ratio is 5 to 10 to 1. The schematic shows the typical values. There is a little loading on the crystal. Variations in device characteristics causes drift and the relatively high values of C2 and C3 “swamp out” variations. C1 is used to tune the frequency. A clean  enough sine wave appears at the emitter of the transistor.

This entry was posted in Oscillators and tagged . Bookmark the permalink.,
Possibly Related to "Colpitts Crystal Oscillator" Circuits

  • High Accuracy Sine Wave Oscillator
    There are many applications that require stability in the operation, such as telecommunications, servos, and test equipment. They are using frequency-accurate sine-wave sources, but to find frequency-accurate sine-wave sources with satisfactory level of absolute accuracy and drift can be a … Continue reading →...
  • Cmos Pair 2-Mhz Crystal Oscillator
    This is a 2 MHz crystal circuit using CMOS pair. This circuit is ideal for uses in digital watches and clock because this circuit has low power drain. The oscillator in this circuit is built by connecting the One CMOS … Continue reading →...
  • 90-125 Mhz Crystal RF Oscillator
    This is a circuit of 90-125 MHz Crystal which is very useful for VHF/UHF converters. This circuit provide 5 to 15 mW output. High-quality fifth- or seventh-over-tone crystal type can be used in this circuit. Undesired oscillation never reach above … Continue reading →...
  • Crystal Oscillator
    Crystal oscillator, especially the low frequency one, can be easily implemented using op-amp as the amplifier. Here is the schematic diagram of such circuit: [Source: National Semiconductor Application Note]...
  • JFET Pierce Crystal Oscillator
    This is a simple JFET pierce crystal oscillator. We can use a wide frequency range of crystal using this circuit without circuit modification. Here is the circuit : This circuit uses Q, 2N3823, that is maintained thus insuring good stability … Continue reading →...

Comments are closed.