ICS9248-143 Datasheet, PDF (1/16 Pages) Integrated Circuit Systems – Frequency Generator & Integrated Buffers for PENTIUM II/IIITM & K6

Integrated
Circuit
Systems, Inc.
ICS9248 - 143
Frequency Generator & Integrated Buffers for PENTIUM II/III^TM & K6
Recommended Application:
440BX, MX, VIAApollo Pro 133,Apollo Pro Media
or MVP4 style chip set, for Note book applications.
Output Features:
• 4 - CPUs @ 2.5V/3.3V
including 1 free running CPUCLK_F
• 9 - SDRAM @ 3.3V
• 7 - PCI @ 3.3V, including 1 free running PCICLK_F
• 1 - PCI Early @ 3.3V
• 1 - 48MHz, @ 3.3V fixed.
• 1 - 24/48MHz @ 3.3V
• 2 - REF @3.3V, 14.318MHz.
Features:
• Up to 137MHz frequency support
• 97MHz to support high-end AMD processor.
• Support power management: CLK, PCI, stop and Power
down Mode from I²C programming.
• Spread spectrum for EMI control
(±.25% & 0 to -0.5% down spread).
• Uses external 14.318MHz crystal
• FS pins for frequency select
Key Specifications:
• CPU Output Jitter @ 2.5V: <300ps
• CPU Output Jitter @ 3.3V: <250ps
• PCI Output Jitter @ 3.3V: <250ps
• CPU Output Skew @ 2.5V: <175ps
• CPU Output Skew @ 3.3V: <175ps
• PCI Output Skew @ 3.3V: <500ps
• PCI Early to PCI Skew @ 3.3V: typ = 3ns
Block Diagram
X1
X2
BUFFER IN
FS(0:3) ⁴
SEL24_48#
CLK_STOP#
PCI_STOP#
CPU2.5_3.3#
SDATA
SCLK
PD#
PLL2
/2
XTAL
OSC
PLL1
Spread
Spectrum
LATCH
4
POR
Control
Logic
Config.
Reg.
STOP
STOP
PCI
CLOCK
DIVDER
STOP
48MHz
24_48MHz
2 ^REF[1:0]
CPUCLK_F
3 ^{CPUCLK [2:0]}
8 ^{SDRAM [7:0]}
SDRAM_F
PCICLK [5:0]
6
PCICLK_F
PCICLK_E
9248-143 Rev C 7/26/00
Pin Configuration
VDDREF
1
*SPREAD/REF0
2
GNDREF
3
X1
4
X2
5
VDDPCI
6
*CPU2.5_3.3#/PCICLK_F
7
*FS3/PCICLK0
8
GNDPCI
9
*SEL24_48#/PCICLK1
10
*SELPCIE_6#/PCICLK2
11
PCICLK3
12
PCICLK4
13
VDDPCI
14
BUFFER IN
15
GNDPCI
16
PCICLK5
17
PCICLK6/PCICLK_E
18
VDDCOR
19
PCI_STOP#
20
*PD#
21
GND48
22
SDATA
23
SCLK
24
48
REF1/FS2*
47
VDDLCPU
46
CPUCLK_F
45
CPUCLK0
44
GNDLCPU
43
CPUCLK1
42
CPUCLK2
41
CLK_STOP#
40
GNDSDR
39
SDRAM_F
38
SDRAM0
37
SDRAM1
36
VDDSDR
35
SDRAM2
34
SDRAM3
33
GNDSDR
32
SDRAM4
31
SDRAM5
30
VDDSDR
29
SDRAM6
28
SDRAM7
27
VDD48
26
48MHz/FS0*
25
24_48MHz/FS1*
48-Pin SSOP and TSSOP
* Internal Pull-up Resistor of 120K to VDD
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)
66.67
100.00
100.30
133.33
105.00
133.37
137.00
75.00
100.00
95.00
97.00
133.33
90.00
96.22
66.82
91.50
PCI
(MHz)
33.33
33.33
33.43
33.33
35.00
33.34
34.25
37.50
33.33
31.67
32.33
33.33
30.00
32.07
33.41
30.50
Pentium is a trademark of Intel Corporation
I²C is a trademark of Philips Corporation
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.