ICS9248-150 Datasheet, PDF (2/10 Pages) Integrated Circuit Systems – Frequency Generator for Multi - Processor Servers

ICS9248-150
General Description
The ICS9248-150 is a main clock for ServerWorks Grand Champion Systems.
Spread spectrum typically reduces system EMI by 8dB to 10dB. This simplifies EMI qualification without resorting to
board design iterations or costly shielding. The ICS9248-150 employs a proprietary closed loop design, which tightly
controls the percentage of spreading over process and temperature variations.
Pin Configuration
PIN NUMBER
1
2, 6, 12, 18, 24, 31,
37, 43,
3
4
5, 9, 15, 21, 28, 34,
40, 47
33, 36, 39, 42, 16,
13, 10, 7
32, 35, 38, 41, 17,
14, 11, 8
19
20
22
23
25, 46
26
29, 30
44
27, 45
48
PIN NAME
PCICLK
VDD
FS0
48MHz
FS1
48MHz#
GND
CPUCLKT (7:0)
CPUCLKC (7:0)
REF
SPREAD#
X1
X2
VDDI REF
VDDA,
I REF
MULTSEL(1:0)
PD#
GNDI REF
GNDA
SEL100/133
TYPE
OUT
PCI clock output
DESCRIPTION
PWR
3.3V power supply
IN
OUT
IN
OUT
Frequency select pin
48MHz clock output
Frequency select pin
Inverted 48MHz clock output
PWR
Ground pins for 3.3V supply
OUT
OUT
OUT
IN
X2 Crystal Input
X1 Crystal Output
"True" clocks of differential pair CPU outputs. These are current
outputs and external resistors are required for voltage bias.
"Complementory" clocks of differential pair CPU outputs. These are
current outputs and external resistors are required for voltage bias.
Reference output 14.318MHz
Invokes Spread Spectrum functionality on the Differential host
clocks, Active Low
14.318MHz Crystal input
14.318MHz Crystal output
PWR
Analog power supply 3.3V
OUT
IN
IN
This pin establishes the reference current for the CPUCLK pairs.
This pin takes a fixed precision resistor tied to ground in order to
establish the required current.
CPU swing select inputs
Invokes power-down mode. Active Low.
PWR
Analog Ground pins for 3.3V supply
IN
CPU Frequency Select. Low=100MHz, High=133MHz
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