ICS9169C-40 Datasheet, PDF (1/6 Pages) Integrated Circuit Systems – System Clock Chip

Integrated
Circuit
Systems, Inc.
ICS9169C-40
System Clock Chip
General Description
The ICS9169C-40 is a Clock Synthesizer chip for Pentium or
Cyrix CPU based motherboards using PCI.
Features include eight CPU clocks and six PCI clocks. A
Reference Output is available equal to the crystal frequency.
The device meets the Pentium power-up stabilization, which
requires that CPU and PCI clocks be stable within 2ms after
power-up.
The ICS9169C-40 clock output are designed for low EMI
emissions. Controlled rise and fall times, unique output
driver circuits and innovative circuit layout techniques enable
the ICS9169C-40 to have lower EMI than other clock
devices.
Features
• 8 selectable CPU clocks up to 75MHz
• Six synchronous PCI clocks
• One Referance Clock at 14.318MHz
• Power-up stabilization time = 2ms on all CPU and PCI
clocks, which meets Intel PentiumPro power-up
• Low CPU and PCI clock jitter <500ps
• Low skew output
• Improved output drivers are designed for low EMI
• Test Mode
• Optional common or mixed supply mode:
(VDD = VDDL1 =VDDL2 = 3.3V)
(VDD = 3.3V, VDDL1=VDDL2 = 2.5)
(VDD = 3.3V, VDDL1 = 3.3V, VDDL2 = 2.5V)
• Space saving and low cost 34-pin SSOP package
The ICS9169C-40 accepts a 14.318MHz reference crystal or
clock as its input and runs from a 3.3V supply.
Block Diagram
Pin Configuration
34-Pin SSOP
Functionality
3.3V±10%, 0-70^°C
Crystal (X1, X2) = 14.31818 MHz
Pentium is a trademark on Intel Corporation.
FS2
FS1
FS0
CPU
PCI
0
0
0
50MHz
33.3MHz
0
0
1
55MHz
36.67MHz
0
1
0
REF/2
REF/4
0
1
1
75MHz
37.5MHz
1
0
0
50MHz
25MHz
1
0
1
55MHz
27.6MHz
1
1
0
60MHz
30MHz
1
1
1
66.6MHz 33.3MHz
9169C-40RevA072897P
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.