85357AG-11

www.icst.com/products/hiperclocks.html

REV. A JULY 25, 2001

7

Integrated

Circuit

Systems, Inc.

ICS85357-11

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.

Figure 6. Crystal Input Interface

XTAL_IN

XTAL_OUT

X1

18pF Parallel Crystal

C1

22p

C2

27p

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

22

27

14.318011

-12

47.46

15.00

22

27

14.999862

-9

47.70

16.66

22

27

16.660162

10

47.70

19.44

22

27

19.440081

4

46.85

24.00

22

27

24.000183

8

46.00