ICS9250-18 Datasheet, PDF (1/15 Pages) Integrated Circuit Systems – Frequency Generator & Integrated Buffers for Celeron & PII/III™

Integrated
Circuit
Systems, Inc.
ICS9250-18
Frequency Generator & Integrated Buffers for Celeron & PII/III™
Recommended Application:
BX, Appollo Pro 133 type of chip set.
Output Features:
• 3 - CPUs @2.5V, up to 166MHz.
• 17 - SDRAM @ 3.3V, up to 166MHz.
• 7 - PCI @3.3V
• 2 - IOAPIC @ 2.5V
• 1 - 48MHz, @3.3V fixed.
• 1 - 24MHz @ 3.3V
• 2 - REF @3.3V, 14.318MHz.
Features:
• Up to 166MHz frequency support
• Support power management: CPU, PCI, stop and Power
down Mode form I²C programming.
• Spread spectrum for EMI control (± 0.25% center spread)
• Uses external 14.318MHz crystal
Key Specifications:
• CPU – CPU: <175ps
• CPU – PCI: 1 - 4ns
• PCI – PCI: <500ps
• SDRAM - SDRAM: <250ps
VDDREF
*FS2/REF1
*PCI_STOP#/REF0
GND
X1
X2
VDDPCI
*MODE/PCICLK_F
*FS3/PCICLK0
GND
PCICLK1
PCICLK2
PCICLK3
PCICLK4
VDDPCI
PCICLK5
BUFFERIN
SDRAM11
SDRAM10
VDDSDR
SDRAM9
SDRAM8
GND
SDRAM15
SDRAM14
GND
{ I ² C
SDATA
SCLK
Pin Configuration
1
56
2
55
3
54
4
53
5
52
6
51
7
50
8
49
9
48
10
47
11
46
12
45
13
44
14
43
15
42
16
41
17
40
18
39
19
38
20
37
21
36
22
35
23
34
24
33
25
32
26
31
27
30
28
29
VDDLIOAPIC
IOAPIC0
IOAPIC_F
GND
CPUCLK_F
CPUCLK1
VDDLCPU
CPUCLK2
GND
CPU_STOP#
SDRAM_F
VDDSDR
SDRAM0
SDRAM1
GND
SDRAM2
SDRAM3
SDRAM4
SDRAM5
VDDSDR
SDRAM6
SDRAM7
GND
SDRAM12
SDRAM13
VDD48
24MHz/FS0*
48MHz/FSI*¹
56-Pin SSOP
Block Diagram
* Internal Pull-up Resistor of 240K to 3.3V on indicated inputs
** Internal Pull-down resistor of 240K to GND on indicated inputs.
1. This output is double strength.
Functionality
FS3 FS2 FS1 FS0
0
0
0
0
0
0
0
1
0
0
1
0
0
0
1
1
0
1
0
0
0
1
0
1
0
1
1
0
0
1
1
1
1
0
0
0
1
0
0
1
1
0
1
0
1
0
1
1
1
1
0
0
1
1
0
1
1
1
1
0
1
1
1
1
CPU
(MHz)
80.00
75.00
83.31
66.9
103.00
112.01
68.01
100.7
120.00
114.99
109.99
105.00
140.00
150.00
124.00
133.9
PCICLK
(MHz)
40.00
37.50
41.65
33.45
34.33
37.34
34.01
33.57
40.00
38.33
36.66
35.00
35.00
37.50
31.00
33.25
9250-18 Rev B 9/23/99
Third party brands and names are the property of their respective owners.
ICS reserves the right to make changes in the device data identified in
this publication without further notice. ICS advises its customers to
obtain the latest version of all device data to verify that any
information being relied upon by the customer is current and accurate.