ICS844256DGI REVISION A AUGUST 5, 2010

3

©2010 Integrated Device Technology, Inc.

ICS844256DI Data Sheet

FEMTOCLOCK® CRYSTAL-TO-LVDS FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER

Function Tables

Table 3. Example Frequency Function Table

Inputs

Function

XTAL (MHz)

FB_SEL

N_SEL1

N_SEL0

M Divider Value

VCO (MHz)

N Divider Value

Output (MHz)

20

0

0

0

25

500

1

500

20

0

0

1

25

500

2

250

20

0

1

0

25

500

4

125

20

0

1

1

25

500

5

100

21.25

0

1

1

25

531.25

5

106.25

24

0

0

0

25

600

1

600

24

0

0

1

25

600

2

300

24

0

1

0

25

600

4

150

24

0

1

1

25

600

5

120

25

0

0

0

25

625

1

625

25

0

0

1

25

625

2

312.5

25

0

1

0

25

625

4

156.25

25

0

1

1

25

625

5

125

25.5

0

1

0

25

637.5

4

159.375

15.625

1

1

1

32

500

8

62.5

18.5625

1

1

1

32

594

8

74.25

18.75

1

0

0

32

600

1

600

18.75

1

0

1

32

600

2

300

18.75

1

1

0

32

600

4

150

18.75

1

1

1

32

600

8

75

19.44

1

0

0

32

622.08

1

622.08

19.44

1

0

1

32

622.08

2

311.04

19.44

1

1

0

32

622.08

4

155.52

19.44

1

1

1

32

622.08

8

77.76

19.53125

1

0

0

32

625

1

625

19.53125

1

0

1

32

625

2

312.5

19.53125

1

1

0

32

625

4

156.25

19.53125

1

1

1

32

625

8

78.125

20

1

1

1

32

640

8

80