Pierce-gate oscillator

Posted on Sep 15, 2012

The Pierce-gate oscillator of Figure 1 is well recognized by most designers, but few understand how to specify the crystal correctly. The crystal used in the topology of Figure 1 can be either a fundamental AT-CUT or BT-CUT. A BT-CUT crystal has poor frequency stability over temperature compared to an AT-CUT. This topology uses a parallel crystal and not a series crystal. When a parallel crystal is specified, the crystal manufacturer will also require that you specify a load capacitance.

Pierce-gate oscillator
Click here to download the full size of the above Circuit.

To understand load capacitance, think of a series LC circuit where the crystal is the L and the load capacitance is the C. The resonance frequency of the LC circuit will vary as a function of L and C. But in the crystal case, the L is fixed (temperatur

Leave Comment

characters left:

New Circuits



Popular Circuits

Sense Small Inductance Changes Over A Wide Range
led metronome circuit
amplifier circuit
Bell Alarm
The FSK modulation circuit composed of 74LS74
Capacitive level measuring circuit
By DC variable speed motor control circuit diagram of an optical fiber