
MC74HC4060A
http://onsemi.com
8
TABLE 1. CRYSTAL OSCILLATOR AMPLIFIER SPECIFICATIONS (TA = 25°C; Input = Pin 11, Output = Pin 10)
Type
Positive Reactance (Pierce)
Input Resistance, Rin
60MW Minimum
Output Impedance, Zout (4.5V Supply)
200W (See Text)
Input Capacitance, Cin
5pF Typical
Output Capacitance, Cout
7pF Typical
Series Capacitance, Ca
5pF Typical
Open Loop Voltage Gain with Output at Full Swing, α
3Vdc Supply
4Vdc Supply
5Vdc Supply
6Vdc Supply
5.0 Expected Minimum
4.0 Expected Minimum
3.3 Expected Minimum
3.1 Expected Minimum
PIERCE CRYSTAL OSCILLATOR DESIGN
Figure 8. Equivalent Crystal Networks
RS
LS
CS
Re
Xe
2
1
2
1
2
1
CO
Value are supplied by crystal manufacturer (parallel resonant crystal).
Figure 9. Series Equivalent Crystal Load
Figure 10. Parasitic Capacitances of the Amplifier
Zload
-jXCo
-jXC2
R
-jXC
-jXCs
jXLs
RS
Rload
Xload
NOTE: C = C1 + Cin and R = R1 + Rout. Co is considered as part of
the load. Ca and Rf typically have minimal effect below 2MHz.
Cin
Cout
Ca
Values are listed in Table 1.