DIN IEC/TS 61994-3:2012-04

Part 3 of the 61994 standard series is a Technical Specification that contains terms and definitions for piezoelectric dielectric oscillators representing the present state-of-the-art. These terms and definitions are intended for use in the standards and documents of IEC/TC 49. Significant clauses of the document contain, amongst others, definitions and clarifications regarding: - decay time, the time interval required for the trailing edge of a waveform to change between two defined levels; - Allan variance of fractional frequency fluctuation, the unbiased estimate of the preferred definition in the time domain of the short-term stability characteristic of the oscillator output frequency; - frequency tolerance, the maximum permissible deviation of the oscillator frequency from a specified nominal value when operating under specified conditions; - linearity of frequency modulation deviation, the measure of the transfer characteristic of a modulation system as compared to its an ideal (straight line) function; - phase jitter, the short-term variations of the zero crossings of the oscillator output signal from their ideal position in time; - operable temperature range, the range of temperature over which the oscillator will continue to provide an output signal. The document also contains general definitions regarding adjustment frequency, amplitude-modulation distortion, rise time, electrostatic discharge, frequency offset, harmonic distortion, long-term frequency stability, spurious oscillations, and crystal cut, amongst others. Furthermore, explanations about the different types of quartz crystal oscillators, such as oven-controlled crystal oscillators (OCXO), temperature compensated crystal oscillators (TCXO) and voltage controlled crystal oscillators (VCXO) are also provided. The responsible committee is K 642 "Piezoelektrische Bauteile zur Frequenzstabilisierung und -selektion" ("Piezoelectric and dielectric devices for frequency control and selection") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.