ICS85357-11 Datasheet, PDF (7/12 Pages) Integrated Circuit Systems – 4:1 OR 2:1, CRYSTAL OSCILLATOR-TO-3.3V LVPECL / ECL MULTIPLEXER

Integrated
Circuit
Systems, Inc.
ICS85357-11
4:1 OR 2:1, CRYSTAL OSCILLATOR-TO-3.3V
LVPECL / ECL MULTIPLEXER
APPLICATION INFORMATION
CRYSTAL INPUT INTERFACE
A crystal can be characterized for either series or parallel mode operation. The ICS85357-11 has a built-in crystal oscillator circuit.
This interface can accept either a series or parallel crystal without additional components and generate frequencies with accuracy
suitable for most applications. Additional accuracy can be achieved by adding two small capacitors C1 and C2 as shown in Figure 6.
Typical results using parallel 18pF crystals are shown in Table 7.
X1
18pF Parallel Crystal
XTAL_IN
C1
22p
XTAL_OUT
C2
27p
Figure 6. Crystal Input Interface
Table 7. Typical Results of Crystal Input Interface Frequency Fine Tuning
Crystal Frequency
C1
C2 Measured Output Frequency Accuracy Duty Cycle
(MHz)
(pF) (pF)
(MHz)
(PPM)
(%)
14.31818
15.00
16.66
19.44
24.00
22
27
22
27
22
27
22
27
22
27
14.318011
14.999862
16.660162
19.440081
24.000183
-12
47.46
-9
47.70
10
47.70
4
46.85
8
46.00
85357AG-11
www.icst.com/products/hiperclocks.html
7
REV. A JULY 25, 2001