WG 11 - TC 49/WG 11

IEC TS 61994-3:2021(E) gives the terms and definitions for piezoelectric, dielectric and electrostatic oscillators representing the state of the art, which are intended for use in the standards and documents of IEC TC 49.
The main changes with respect to the previous edition are as listed below:
- some definitions have been updated;
- the terminology given in IEC 60679-1:2017 has been taken into account;
- new terminologies are added.

IEC TS 61994-4-4:2018 is available as IEC TS 61994-4-4:2018 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC 61994-4-4:2018 gives the terms and definition for single crystal wafers for surface acoustic wave (SAW) devices representing the state of the art. This edition includes the following significant technical changes with respect to the previous edition:
- the new terms and definitions given in IEC 62276:2016 have been taken into account;
- the general title has been changed according to the change in the title of TC 49 in 2009.
- the part title has been changed according to the title of IEC 62276:2016.

IEC TS 61994-4-1:2018 is available as IEC TS 61994-4-1:2018 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC 61994-4-1:2018 gives the terms and definition for synthetic quartz crystals representing the state of the art, which are intended for manufacturing piezoelectric and optical elements. This edition includes the following significant technical changes with respect to the previous edition:
- The new terms and definitions given in IEC 60758:2016 have been taken into account;
- The general title has been changed according to the change in the title of TC 49 in 2009.

IEC 60444-8:2016 describes test fixtures suitable for leadless surface mounted quartz crystal units in enclosures as defined in IEC 61837 (all parts). These fixtures allow the measurement of (series) resonance frequency, (series) resonance resistance, and equivalent electrical circuit parameters L1, C1 and C0 using the measurement techniques specified in IEC 60444-5 and for the determination of load resonance frequency and load resonance resistance according to IEC TR 60444-4 and IEC 60444-11.
Two test fixtures are described in this document:
1) A fixture using the p-network circuit with electrical values as described in IEC 60444-1 for measurements in transmission mode up to 500 MHz. This fixture includes optional means to add physical load capacitors for the measurement of load resonance parameters up to 30 MHz in accordance with IEC 60444-4. The range of load capacitance is 10 pF or more. Calibration of the measurement system and CL adapter board is explained hereinafter.
2) A fixture based on the reflection method, suitable for a frequency range up to 1 200 MHz. No provisions for adding a physical load capacitance are anticipated. Load resonance parameters can be measured by using the method of IEC 60444-11.
This edition includes the following significant technical changes with respect to the previous edition:
a) modification of Clause 1;
b) modification of 5.2;
c) modification of 5.3;
d) modification of 5.4;
e) 6.3 Calibration of the reflection measurement system.

IEC 60444-6:2013 applies to the measurements of drive level dependence (DLD) of quartz crystal units. Two test methods and one referential method are described. This edition includes the following significant technical changes with respect to the previous edition:
a) DLD measurement with oscillation circuit had the traditional method to detect the DLD abnormal modes at present time. Therefore, this method made the transition to the Annex B.
b) High reliability crystal unit is needed to use for various applications at the present day, in order to upgrade the inspection capabilities for DLD abnormal modes, the multi-level reference measurement method was introduced into this specification.

IEC/TS 61994-3:2011(E) specifies the terms and definitions for piezoelectric dielectric oscillators representing the state-of-the-art, which are intended for use in the standards and documents of IEC TC 49.

IEC/TS 61994-2:2011 is a technical specification that gives the terms and definitions for piezoelectric and dielectric filters representing the present state of the art, which are intended for use in the standards and documents of IEC technical committee 49. The main changes with respect to the previous edition are listed below:
- definitions updated,
- terminology given in orderly sequence,
- new terminologies are added,
- drawings inserted for easier understanding.

IEC/TS 61994-4-2:2011 specifies the terms and definitions for piezoelectric ceramics representing the present state-of-the-art, which are intended for use in the standards and documents of IEC technical committee 49. The main changes with respect to the previous edition are:
- definitions updated;
- terminology given in orderly sequence;
- drawing inserted for easier understanding the vibration modes.

IEC 60444-11:2010 defines the standard method of measuring load resonance frequency fL at the nominal value of CL, and the determination of the effective load capacitance CLeff at the nominal frequency for crystals with the figure of merit M > 4.

IEC 61994-4-4:2010(E) specifies the terms and definitions for single crystal wafers applied for surface acoustic wave (SAW) devices representing the state of the art, which are intended for use in the standards and documents of IEC technical committee 49. This second edition cancels and replaces the first edition published in 2005. The main changes with respect to the previous edition are listed below:
- Terms and definitions are rearranged in accordance with the order of the alphabet.
- "reduced LN" is appended to terms and definitions.
- "reduced LT" is appended to terms and definitions.
- reduction process is appended to terms and definitions.

IEC 60689:2008 applies to measurements and test methods for tuning fork quartz crystal units in the range from 10 kHz to 200 kHz and standard values for frequency control and selection. This edition includes the following significant technical changes with respect to the previous edition: a) The title of the first edition is Measurements and test methods for 32 kHz quartz crystal units for wrist watches and standard values. The title is modified and the frequency range of this second edition is extended to the range from 10 kHz to 200 kHz. b) The Lissajous method is defined in the first edition as the standard measurement method. The PI network and bridge method are used in this second edition. c) The PI network has a transformer for impedance matching. This composition differs from that of IEC 60444-1.

Gives the terms and definitions for piezoelectric and dielectric resonators representing the present state-of-the-art, which are intended for use in the standards and documents of IEC TC 49. This new edition takes into account new editions of IEC TC 49 publications.

IEC 60444-9:2007 describes two methods for determining the spurious (unwanted) modes of piezoelectric crystal resonators. It extends the capabilities and improves the reproducibility and accuracy compared to previous methods.

IEC 60444-7:2004 applies to activity and frequency dips for quartz crystal units over a temperature range.

IEC 60679-6:2011 applies to the phase jitter measurement of quartz crystal oscillators and SAW oscillators used for electronic devices and gives guidance for phase jitter that allows the accurate measurement of r.m.s. jitter. In the measurement method, phase noise measurement equipment or a phase noise measurement system is used. The measuring frequency range is from 10 MHz to 1 000 MHz. This standard applies to quartz crystal oscillators and SAW oscillators used in electronic devices and modules that have the multiplication or division functions based on these oscillators. The type of phase jitter applied to these oscillators is the r.m.s. jitter. This standard cancels and replaces IEC/PAS 60679-6 published in 2008. This first edition constitutes a technical revision.