Application Notes - Rakon

Guidelines for use of Mercury Miniature OCXOs in Network Timing Applications

Gives best practice advice on how to optimise the performance of miniature Mercury OCXOs (IQD's IQOV-71) in network timing and synchronisation applications. In a conventional OCXO, to improve frequency stability, the effect of ambient temperature is virtually eliminated by enclosing the entire oscillator within an 'oven' maintained at a constant high temperature ......


Single Transistor Crystal Oscillator Circuits

For an electronic circuit to oscillate there are two criteria which must be satisfied. Must contain an amplifier with sufficient gain to overcome the losses of the feedback network (Quartz Crystal in this case) and the phase shift around the whole circuit is 0° or some integer multiple of 360°. To design a crystal oscillator the above has to be true but there are a myriad of other considerations including crystal power dissipation, unwanted mode suppression, crystal loading (the actual impedance the crystal sees once oscillation has started) and the introduction of a non-linearity in the gain to limit the oscillation build-up ......


IC Crystal Oscillator Circuits

The majority of ICs with built in crystal oscillator circuits use the Gated Pierce design where the oscillator is built around a single CMOS inverting gate. For oscillator applications this is usually a single inverting stage comprising one P channel and one N channel enhancement-mode MOSFET, more commonly known in the digital world as an Un-Buffered Inverter. It is possible to use a Buffered Inverter (usually comprising three P-N MOSFET pairs in series) but the associated gain of many thousands will lead to a potentially less stable finished oscillator ......