zl30112 Zarlink Semiconductor, zl30112 Datasheet - Page 11

• Manufacturer Part Number: zl30112
• Description: Slic/codec Dpll
• Manufacturer: Zarlink Semiconductor

The output clock should be connected directly (not AC coupled) to the OSCi input of the ZL30112 and the OSCo
output should be left open as shown in Figure 6.
6.2.2
Alternatively, a Crystal Oscillator may be used. A complete oscillator circuit made up of a crystal, resistor and
capacitors is shown in Figure 7.
The accuracy of a crystal oscillator depends on the crystal tolerance as well as the load capacitance tolerance.
Typically, for a 20 MHz crystal specified with a 32 pF load capacitance, each 1 pF change in load capacitance
contributes approximately 9 ppm to the frequency deviation. Consequently, capacitor tolerances and stray
capacitances have a major effect on the accuracy of the oscillator frequency.
The crystal should be a fundamental mode type - not an overtone. The fundamental mode crystal permits a simpler
oscillator circuit with no additional filter components and is less likely to generate spurious responses. The crystal
specification is as follows.
Crystal Oscillator
1
2
3
4
5
6
Table 2 - Typical Crystal Oscillator Specification
Frequency
Tolerance
Oscillation Mode
Resonance Mode
Load Capacitance
Maximum Series Resistance
ZL30112
Figure 6 - Clock Oscillator Circuit
OSCo
OSCi
No Connection
Zarlink Semiconductor Inc.
ZL30112
20 MHz OUT
11
+3.3 V
+3.3 V
GND
20 MHz
As required
Fundamental
Parallel
As required
50 Ω
0.1 µF
Data Sheet