ZL50022
Data Sheet
Load Capacitance
20 pF - 32 pF
Maximum Series Resistance
Approximate Drive Level
35 Ω
1 mW
25.1.2 External Clock Oscillator
When an external clock oscillator is used, numerous parameters must be considered. They include absolute
frequency, frequency change over temperature, output rise and fall times, output levels and duty cycle.
The output clock should be connected directly (not AC coupled) to the OSCi input of the device, and the OSCo
output should be left open as shown in Figure 24 on page 91. XC is a buffered version of the 20 MHz input clock
connected to the internal circuitry.
+3.3 V
OSCi
4K DX
+3.3 V
20 MHz OUT
GND
0.1 uF
OSCo
XC
No Connection
Figure 24 - Clock Oscillator Circuit
For applications requiring ±32 ppm clock accuracy, the following requirements should be met:
Frequency
20.000 MHz
±32 ppm
Tolerance
Rise and Fall Time
Duty Cycle
10 ns
40% to 60%
91
Zarlink Semiconductor Inc.
ZARLINK [ ZARLINK SEMICONDUCTOR INC ]
