Keltron Crystals Ltd

Product Parameters and Specifications

To ensure optimum performance from your equipment, your KELTRON Crystals will have to be custom-built to match your circuit conditions. Please therefore specify the following while ordering your KELTRON Crystals:

	Crystal frequency
	Holder type
	Mode of oscillation
	Resonance – Series or Parallel
	Load capacitance value (for Parallel Resonance)- Please see note
	Operating temperature range (O.T.R)
	Frequency tolerance (at 25C and /or over the O.T.R)
	Equivalent Series Resistance and other additional parameters if specific values are required, otherwise standard values will be assumed.

Note on load capacitance : This is the effective capacitance of the total circuit treated as a lumped capacitance in series with the Crystal. To achieve the nominal frequency within the required tolerances it is important that the load capacitance value given in the specifications must be exactly the same as that which is actually offered to the Crystal by the user’s circuit. In case of difficulty in assessing the load capacitance value of your circuit, KELTRON will be glad to offer you all necessary application oriented-assistance for finalising the Crystals specifications.

A few combinations of parameters are shown in the accompanying table to illustrate out product range. This table is only indicative but not exhaustive as KELTRON specialises in designing Crystals to suit individual customer preferences.

Frequency range	Holder	Mode of oscillation	Frequency Tolerance	Resonance Series or Parallel
1-600 KHz	HC-13/U	”	± 0.02% ove r –20 to 70 ° C	S/P	Some of the standard load capacitance values are 16 pF 20pF, 30pF,32pF. Other values available on request . For series resonance the load capacitance is infinity
200-600 KHz	HC-6/U HC-48/U	”	± 0.15% ove r –20 to 70 ° C	S/P
0.8-3 MHz	”	”	± 0.005% ove r –55 to+105 °C	S/P
3-25 MHz	HC-48/U HC-49/U HC-50/U	”	”
18-60 MHz	”	Third Overtone	”	S
50-125 MHz	”	Fifth Overtone	”	S
125-150 MHz	”	Seventh Overtone		S
4.433619 MHz 8.867238 MHz (for CTV)	HC-49/U	Fundamental	± 0.003% ove r –10 to +60 ° C	S/P
32.768 KHz (Tuning Fork)	Cylindrical 3x8 mm	Fundamental	± 0.002% supplied in tolerance groups of ± 0.0005%	P	12.5 pF

Standard Microprocessor Frequencies like 3.579545 MHz, 4.000 MHz, 4.194 MHz, 6.000 MHz ,
8.000 MHz, 10.000 MHz, 12.000 MHz, 16.000 MHz, 20.000 MHz, 24.000 MHz etc
are available ex-stock at very attractive prices