APPROVED PRODUCT
C9777
Low EMI Clock Generator for 440BX, ALi1631 & Via Pro133
+
/ Pentium
®
III Systems
Product Features
•
•
•
•
•
•
•
•
•
•
•
•
•
Supports Pentium II and Pentium III CPU’s.
Designed to meet Intel 440BX/ZX chipset
specification
+
Supports Via Pro 133 and ALi1631 chipsets
4 CPU clocks with isolated power supply
8 PCI clocks
2 48 MHz for USB clock
3 Reference clocks
2 IOAPIC clocks
< 175 pS Max. Skew among CPU clocks.
< 500 pS Max. Skew among PCI clocks.
Smooth frequency switching for jumperless
application
48-pin SSOP package
Spread Spectrum for EMI reduction
®
®
Frequency Table
S2
0
0
0
0
1
1
1
1
S1
0
0
1
1
0
0
1
1
S0
0
1
0
1
0
1
0
1
CPU
133.63
143.18
153.92
66.82
124.09
133.63
112.16
100.23
Table 1
PCI
33.4
35.79
38.48
33.41
41.36
44.54
37.39
33.41
Block Diagram
XIN
36pF
300K
XBUF
XOUT
36pF
2
1
VDD
REF1
VDD
PLL1
Rin
S0
S1
S2
Pwr_Dwn#
CPU_stp#
PCI_stp#
VDDI
2
VDDC
4
VDD
SSON#
SMBW
PLL2
1
Rin
VDD
SIO
1
24/48 MHz
8
VDD
48MHZ
PCI(_F,1:7)
CPU(1:4)
IOAPIC(1:2)
2
REF2
REF3
VDD
Pin Configuration
REF1 / SIO
REF2 / SDWN#
VSS
XIN
XOUT
VSS
PCI F
PCI1
VDD
PCI2
PCI3
VSS
PCI4
PCI5
VDD
PCI6
PCI7
VSS
VDD
VSS
VDD
48MHz
48 / 24 MHz
VSS
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
VDD
REF3
VDDI
IOAPCI1
IOAPIC2
VSS
SMBW
VDDC
CPU1
CPU2
VSS
VDDC
CPU3
CPU4
VSS
VDD
VSS
PCI stp#
CPU stp#
Pwr Dwn#
SSON#
S0
S1
S2
Fig.1
Cypress Semiconductor Corporation
525 Los Coches St.
Milpitas, CA 95035. Tel: 408-263-6300, Fax: 408-263-6571
http://www.cypress.com
Document#: 38-07048 Rev. **
05/02/2001
Page 1 of 12
CYPRESS [ CYPRESS SEMICONDUCTOR ]
