PD IEC PAS 62277:2002 pdf download Test-fixture of surface mounting quartz crystal units
2. Scope
This document describes the test-ixture that allows the accurate measurement ofresonance frequency, resonance resistance, and electrical-equivalent-circuit constantsof a leadless surface mounting quartz crystal units using the zero phase technique asspecified in IEC 60444-4 (4] and IEC 60444-5. Then, an equivalent circuit constant andthe application frequency range obtained by using the test-ixture are shown. Inaddition, this is applied to Enclosure shown with IEC 61240 [5] as crystal unit with nolead wire. An equivalent circuit of the test-fixture and an electric value are based onIEC 60444-1[6] and IEC 60444-4. The range of load capacitance is 7 pF for 1 ppmaccuracy or more. The calibration of measurement system and Cl adapter board isexplained.
3.Application
This document shall be applied to the test-fixture that allows the accuratemeasurement of resonance frequency, resonance resistance, parallel capacitance Co,motional capacitance Cl, and motional inductance Li of the crystal unit over thefrequency range of 1 MHz to 30 MHz using an automatic network analyzer, based onIEC 60444-5
4.General issue
The test-ixture and the method for measuring the resonance frequency, resonanceresistance. and electrical-equivalent-circuit constants may be specified in the contractbetween the unit supplier and the user. The leadless crystal unit requires specialconsideration.
5Leadless surface mounting quartz crystal units5.1 Enclosure
No particular specification shall be made regarding the holder type. However, it isrecommended those shown in IEC 61240 show be used.
5.2 Overtone and frequency range
No particular specification shall be made regarding the overtone. The frequencyrange is from 1 MHz to 150 MHz when the load capacitance is not used, and is from1 MHz to 30 MHz when the load capacitance is used.
6.Specifications of measurement method, test-fixture
61 Specifications of measurement method
The measurement method is according to IEC 60444-5, using the admittance circletechnique.
62 Specifications of test-fixture
An equivalent circuit of the test-fixture and an electric value are based on IEC 60444-1.The size and the structure are different in this proposal from IEC 60444-1. The sizeand the structure are more suitable for leadless crystal unit.
The test-ixture configuration is as specified in IEC 60444-1. Figure 1 and figure 2shows the edge valet, but maximum circuit stray capacitance (0.5 pF) betweenmeasurement terminals such as Ctl, Ct2 in Figure 1 of IEC 60444-1 are not specifiedFigure 3 and figure 4 show a suggested 3-D view and dimensions for the test-fixtureigure 5 is structure of the test-ixture. A minicontact force of 2 N is required toensure satisfactory connection.