WG 1 - TC 49/WG 1

IEC 60122-2:2025 has been compiled in response to a generally expressed desire on the part of both users and manufacturers for guidelines to the use of quartz crystal units for filters and oscillators so that the crystal units may be used to their best advantage.
It draws attention to some of the more fundamental questions which will be considered by the user before it places its order for a unit for a new application, and in so doing will, it is hoped, help ensure against unsatisfactory performance, unfavourable cost and non-availability. It is not the function of this document to explain theory, nor to attempt to cover all the eventualities that can arise in practical circumstances. Lastly, it it is not considered as a substitute for close liaison between manufacturer and user.
Standard specifications, such as those of the IEC of which these guidelines form a part, and national specifications or detail specifications issued by manufacturers, will define the available combinations of the resonant characteristics and the temperature characteristic. These specifications are compiled to include a wide range of quartz crystal units with standardized performances. It cannot be over-emphasized that it is the responsibility of the user , wherever possible, to select the quartz crystal units from these specifications, when available, even if it can lead to making small modifications to the circuit to enable the use of standard resonators. This applies particularly to the selection of the nominal frequency.
This edition includes the following significant technical changes with respect to the previous edition:
a) addition of SC cut type and related requirements;
b) addition of ageing calculation and low level of drive requirements according to the general specification,
c) update of the frequency temperature curve according to the common cut requirements;
d) removal of infrequently used product types.

IEC 60444-6:2021 applies to the measurements of drive level dependence (DLD) of quartz crystal units. Two test methods (A and C) and one referential method (B) are described. “Method A”, based on the p-network according to IEC 60444-5, can be used in the complete frequency range covered by this part of IEC 60444. “Reference Method B”, based on the p-network or reflection method according to IEC 60444-5 or IEC 60444-8 can be used in the complete frequency range covered by this part of IEC 60444. “Method C”, an oscillator method, is suitable for measurements of fundamental mode crystal units in larger quantities with fixed conditions.
NOTE The measurement methods specified in this document are not only applicable to AT-cut, but also to other crystal cuts and vibration modes, such as doubly rotated cuts (IT,SC) and to tuning fork crystal units (by using a high impedance test fixture). This edition includes the following significant technical changes with respect to the previous edition:
- some equations have been removed and corrected;
- it has been specified in the note of the Scope that the measurement methods specified in this document are not only applicable to AT-cut but also to other crystal cuts and vibration modes.

IEC 60122-4:2019 is applicable to crystal units with thermistors mainly used in the field of mobile communication that requires high frequency stability such as local reference signal generator for the mobile phone base station or GPS. This document provides users with technical guidelines of crystal units with thermistors as well as basic knowledge of common crystal units with thermistors

Describes a high-performance backplane bus for use in microprocessor bases systems. This parallel bus supports single- and block-transfer cycles on a 32-bit non-multiplexed address and data highway. Transmission is governed by an asynchronous handshaken protocol. The bus allocation provides for multiprocessor architectures. This bus also supports inter-module interrupts for facilitating quick response to internal and external events. The mechanics of the boards and chassis are based on IEC 60297.[
]Note: -1.This bus is similar to the VME bus. 2.For the price of this publication, please consult the ISO/IEC price-code list.

Specifies the methods of test and general requirements for quartz crystal units of assessed quality using either capability approval or qualification approval procedures.

Is a supplementary document to the sectional specification and contains requirements for the minimum content of detail specifications.

Prescribes the preferred ratings and characteristics, with appropriate tests and measuring methods contained in the generic specification, IEC 60368-1, and gives the general performance requirements to be used in detail specifications for piezoelectric filters.

Specifies the methods of test and general requirements for piezoelectric filters of assessed quality using either capability approval or qualification approval procedures.