Z8 Encore! XP® 4K Series
Product Specification
186
The stabilization time will vary depending on the crystal or resonator used, as well as on
the feedback network. See Table 114 for transconductance values to compute oscillator
stabilization times.
Note:
Figure 27 illustrates a recommended configuration for connection with an external funda-
mental-mode, parallel-resonant crystal operating at 20 MHz. Recommended 20 MHz crys-
tal specifications are provided in Table 113. Resistor R1 is optional and limits total power
dissipation by the crystal. Printed circuit board layout must add no more than 4 pF of stray
capacitance to either the XIN or XOUT pins. If oscillation does not occur, reduce the values
of capacitors C1 and C2 to decrease loading.
On-Chip Oscillator
XIN
XOUT
Crystal
C1 = 15pF
C2 = 15pF
Figure 27.Recommended 20 MHz Crystal Oscillator Configuration
Table 113. Recommended Crystal Oscillator Specifications
Parameter
Frequency
Resonance
Mode
Value
20
Units
Comments
MHz
Parallel
Fundamental
60
Series Resistance (R )
W
Maximum
S
PS022815-0206
Crystal Oscillator
ZILOG [ ZILOG, INC. ]
