SN EN 60444-6 : 1997

Committees responsible
National foreword
Introduction
1 General
    1.1 Scope
    1.2 Normative references
2 DLD effects
    2.1 Reversible changes in frequency and resistance
    2.2 Irreversible changes in frequency and
          resistance
    2.3 Causes of DLD effects
3 Drive levels for DLD measurement
4 Test methods
    4.1 Test method A (pi-network method)
    4.2 Test method B (oscillator method)
Annex
A (normative) Relationship between electrical drive level
    and mechanical displacement of quartz crystal units
Figures
1 Maximum tolerable resistance ratio y for the drive
    level dependence as a function of the resistances Rr2 or
    Rr3
2 Insertion of a quartz crystal unit in an oscillator
3 Crystal unit loss resistance as a function of
    dissipated power
4 Behaviour of the Rr of a quartz crystal unit
5 Block diagram of method B
6 Installed -Rosc in scanned drive level range
7 Drive level behaviour of a quartz crystal unit as a
    function of drive level focused against an installed
    -Rosc as a test limit in the method B test
8 Principal schematic diagram of the go/no-go test
    circuit of method B
Annex ZA (normative) Normative references to international
publications with their corresponding European publications

Applicable to measurements of drive level dependence (DLD) of quartz crystal units. Covers two test methods: A, based on the pi-network method in accordance with IEC 444-1, for use in the complete frequency range covered by this part of IEC 444 and B, an oscillator method for measuring fundamental mode crystal units in larger quantities, having fixed conditions.