Integrated
Circuit
Systems, Inc.
9154A
0174E—03/18/08
Low-Cost 16-Pin Frequency Generator
The 9154A is a 0.8mm version of the industry leading 9154.
Like the 9154, the 9154A is a low-cost frequency generator
designed for general purpose PC and disk drive applications.
However, because the 9154A uses 0.8mm technology and
the latest phase-locked loop architecture, it offers
performance advantages that enable the device to be sold
into Pentium™ systems.
The 9154A guarantees a 45/55 duty cycle over all
frequencies. In addition, a worst case jitter of ±250ps is
specified at Pentium frequencies.
The CPU clock offers the unique feature of smooth, glitch-
free transitions from one frequency to the next, making this
the ideal device to use when slowing the CPU speed. The
9154A makes a gradual transition between frequencies so
that it obeys the Intel cycle-to-cycle timing specifications for
486 and Pentium systems.
The 9154A-42 and 9154A-43 devices offer features
specifically for green PCs. The 9154A-42 and -43 have a
single pin that, when pulled low, will smoothly slow the 2XCPU
clock to 8 MHz. This is ideal for dynamic DX microprocessors.
The 9154A-43 not only has the slow clock feature, but also
offers a glitch-free stop clock for static SX microprocessors.
The STOPCLK# pin, when pulled low, enables the 2XCPU
clock to go low only after completing its last full cycle. The
clock continues to run internally, and will be output again on
the first full cycle immediately following stop clock disable.
The simultaneous 2X and 1X CPU clocks offer controlled
skew to within 500ps of each other (-42 only).
ICS has been shipping motherboard frequency generators
since April 1990, and is the leader in the area of multiple
output clocks on a single chip. Consult ICS for all your clock
generation needs.
• Compatible with 386, 486 and Pentium CPUs
• 45/55 Duty cycle
• Runs up to 66 MHz at 3.3V
• Single pin can slow clock to 8 MHz (on -42 and -43)
• Single pin can stop the CPU clock glitch-free (on -43)
• Very low jitter, ±250ps for Pentium frequencies
• 1X and 2X CPU clocks skew controlled to ±250ps (-42
only)
• Smooth transitions between all CPU frequencies
• Slow frequency ramp at power-on avoids CPU lock-up
• 16-pin 150-mil skinny SOIC packages
• 0.8µm CMOS technology
Applications
Computer motherboards: The 9154A replaces crystals and
oscillators, saving board space, component cost, part count
and inventory costs. It produces a switchable CPU clock and
up to four fixed clocks to drive floppy disk, communications,
super I/O, Bus, and/or keyboard devices. The small package
and 3.3V operation is perfect for handheld computers.
Features
General Description
Block Diagram
2
Integrated
Circuit
Systems, Inc.
9154A
0174E—03/18/08
Pin Configuration
16-SOIC
9154A-27CS16
16-SOIC
9154A-42CS16
16-SOIC
9154A-43CS16
Description of new pin:
SLOWCLK# forces 2XCPUCLK
output to ramp smoothly to 8MHz
and CPUCLK output to 4 MHz
when pulled low.
Description of new pis:
SLOWCLK# forces 2XCPUCLK
output to ramp smoothly to 8MHz
when pulled low. STOPCLK#
provides gilitch-free stop of the
2XCPUCLK output when pulled
low. When raised back high, the
2XCPUCLK output clock
resumes full speed operation (no
clock frequency ramp up since
the internal VCO is not stopped).
16-SOIC
9154A-04CS16
16-SOIC
9154A-10CS16
16-SOIC
9154A-26CS16
OBSOLETE
3
Integrated
Circuit
Systems, Inc.
9154A
0174E—03/18/08
Stop Clock Feature
The 9154A-43 incorporates a unique stop clock feature compatible with static logic processors. When the stop clock pin goes
low, the 2XCPUCLK will go low after the next occurring falling edge. When STOPCLK again goes high, 2XCPUCLK resumes
on the next rising edge of the internal clock. This feature enables fast, glitch-free starts and stops of the 2XCPUCLK and is
guaranteed that the CPU does not receive any short period clocks.
2XCPUCLK
STOPCLK#
4
Integrated
Circuit
Systems, Inc.
9154A
0174E—03/18/08
Pin Descriptions
Frequencies based upon 14.318 MHz input)
Note:
Internal Pull-up Resistors.
* -04 and -10 have no pull-ups or frequency select pins
** -10 has no pull-up or Pin 9 PDFCLK
-4 -10 -26 -27 -42 -43
444444 VDD PDigital power (3.3 or 5V).
13 13 13 13 13 13 V DD P Digit al power (3.3 or 5V).
555555 GND PDigital ground.
12 12 12 12 12 12 GDD P Digital g round.
888888 AGND PAnalog ground.
1161161 1 FS0 IFrequency select 0 for CPU clock
(has internal pull-up).*
16 15 16 15 16 16 FS1 I Frequency select 1 for CPU clock
(has internal pull-up).*
10 - 10 10 9 10 FS2 I Frequency select 2 for CPU clock
(has internal pull-up).*
- - 9 9 - - OE I Tri st ates out pu ts when low (has int ernal pul l -up).*
----1515SLOWCLK#I
S l ows 2XCPU cl ock to 8 M Hz (act i ve l ow)
(has in tern al pu l l -up).
-----9STOPCLK#I
S tops 2XCPU cl ock gli tch-free (ac ti ve l ow)
(has in tern al pu l l -up).
333333 X1 ICrystal In.
222222 X2 OCrystal Out.
11 10 11 11 10 11 14.318 M Hz O 14. 3 18 M Hz reference c l ock outp ut.
- 7 1 - - 1. 84 M Hz O 1.84 M Hz (c omm ) c l oc k output .
6116666 24 MHz O24 MHz (floppy disk) clock output.
- 6 - - - - 16 MHz O 16 MHz c l oc k output .
- - 7 7 - - 12 M Hz O 12 MHz key b oard cl ock ou tpu t.
7 1 - - 7 7 8 MHz O 8 MHz k e yboard cl ock ou t put.
14 1 4 14 - 11 - CPUCLK O CPU clo ck output.
15 - 1 5 14 14 1 4 2XCP UCLK O 2X CP U cl ock output.
9----- PD# IPower-Down All (active low) (has internal pull-up).
- 9 - - - - PDFCLK# I P ower-Down Fi x ed Cloc k
(1. 8 4, 8, 16, 24) (act i ve l o w). *
P IN NUM BER P IN NAM E T YP E DES CRIPT ION
5
Integrated
Circuit
Systems, Inc.
9154A
0174E—03/18/08
Fixed Clock Output
Actual Frequencies
(using 14.318 MHz input,
all frequencies in MHz)
14.318
1.84
24.0
12.0
8.0
-10
2XCPU CPU CPUCLK
0 100* 50* PDCPU
180*40*40
2 66.6 33.3 50
3502566.6
44020 -
53216 -
62412 -
7168 -
-
Clock Tables in MHz
for -04 and -10
(using 14.318 MHz input,
all frequencies in MHz)
-04
FS(3:0)
FS(2:0) 2XCPU
(MHz) CPUCLK
(MHz)
0 100.23* 50.11
1 80.18* 40.09
2 66.48* 33.24
3 50.11 25.06
4 40.09 20.05
5 32.22 16.11
6 24.23 12.12
7 15.75 7.88
Clock Table for 9154A-26
(using 14.318 MHz input,
all frequencies in MHz)
-43
2XCPUCLK
2XCPUCLK CPUCLK
^
0 0 0 75* 16 8 16
0 0 1 32 40 20 40
0 1 0 60 33.33 16.67 33.33
0 1 1 40 25 12.5 25
1 0 0 50 60 30 60
1 0 1 66.66 20 10 20
1 1 0 80* 66.66 33.33 66.66
1 1 1 52 50 25 50
-43
2XCPUCLK CPUCLK 2XCPUCLK
0 0 0 75.17* 16.00 8.00 16.00
0 0 1 31.94 40.09 20.05 40.09
0 1 0 60.14 33.41 16.71 33.41
0 1 1 40.09 25.06 12.55 25.06
1 0 0 50.11 60.14 30.07 60.14
1 0 1 66.48 20.05 10.03 20.05
1 1 0 80.18* 66.48 33.24 66.48
1 1 1 51.90 50.11 25.06 50.11
Actual Frequencies
(using 14.318 MHz input, all frequencies in MHz)
FS2 FS1 FS0 -27
2XCPUCLK
-42
-42
Clock Tables
(using 14.318 MHz input, all frequencies in MHz)
FS2 FS1 FS0 -27
2XCPUCLK
6
Integrated
Circuit
Systems, Inc.
9154A
0174E—03/18/08
Absolute Maximum Ratings
VDD referenced to GND .......................................................................... 7.0 V
Voltage on I/O pins referenced to GND . . . . . . . GND - 0.5 V to VDD + 0.5 V
Operating Temperature under bias . . . . . . . . . . 0 to +70 ºC
Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . 0.5 W
Storage Temperature . . . . . . . . . . . . . . . . . . . . . -40 to +150 ºC
Stresses above those listed under
Absolute Maximum Ratings
may cause permanent damage to the device. These ratings
are stess specifications only and functional operation of the device at these or any other conditions above those listed in the
operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended
periods may affect product reliability.
VDD = 3.3 V ± 10%, TA = 0 - 70 oC unless otherwise stated
Electrical Characteristics at 3.3 V
Notes:
1. Parameter is guaranteed by design and characterization.
PARAMETER SYMBOL TE ST CONDITIONS MIN TYP MAX UNITS
Input L ow Vol tage V IL - - 0.2 VDD V
Input High Vol tage V IH 0. 7 V - - V
Input L ow Current IIL VIN = 0V (pul l-up pi n ) - 2 .5 7 A
Input High Current IIH V IN = V DD -5 - 5 A
Output Low Vol tage V O L IOL = 6m A - 0. 05 V DD 0. 1 VDD V
Out put Hi gh V olt age1 V OH IOH = -4mA 0. 85 VDD 0. 94 V DD - V
Output Low Current1 IOL V O L = 0.2VDD 15 24 - m A
Output Hi gh Current1 IOH V OH = 0.7V DD - -13 -8 mA
S upply Current IDD unloaded, 60 MHz - 16 34 mA
Output Frequen c y Chang e over
S upply and Temperature1 F D Wi t h respect to t ypi cal frequency - 0. 00 2 0. 01 %
S hort c i rc uit current 1 IS C eac h out put c loc k 20 30 - mA
Input Capacitance1 CI except X1, X2 - - 10 pF
Load Capaci t an c e 1 CL pi ns X1, X2 - 20 - pF
P ul l -up Resistor1 Rpu at VDD - 0.5V - 620 9 00 k ohm
DC Characteristics
7
Integrated
Circuit
Systems, Inc.
9154A
0174E—03/18/08
Electrical Characteristics at 3.3 V
VDD = 3.3 V ± 10%, TA = 0 - 70 oC unless otherwise stated
Notes:
1. Parameter is guaranteed by design and characterization. Not subject to production testing.
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8
Integrated
Circuit
Systems, Inc.
9154A
0174E—03/18/08
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Notes:
1. Parameter is guaranteed by design and characterization. Not subject to production testing.
VDD = +5 ± 10% V, TA = 0 - 70oC unless otherwise stated
9
Integrated
Circuit
Systems, Inc.
9154A
0174E—03/18/08
Electrical Characteristics at 5.0 V
VDD = +5 ±10% V, TA = 0 - 70oC unless otherwise stated
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Notes:
1. Parameter is guaranteed by design and characterization. Not subject to production testing.
10
Integrated
Circuit
Systems, Inc.
9154A
0174E—03/18/08
0.390
0.031
0.024
0.016
0.050
0.063
0.006±0.004
0.238
0.154
0.008
0.015
0.025
16-Pin SOIC Package
Ordering Information
9154A-27CS16
9154A-42CS16
9154A-04CS16
9154A-10CS16
Example:
Lead Free, RoHS Compliant (Optional)
Lead Count
Package Type
S = SOIC
Pattern Number (2 digit number for parts with ROM-code patterns)
Device Type
9154A - PPC S 16 LF
9154A-43CS16
11
Integrated
Circuit
Systems, Inc.
9154A
0174E—03/18/08
Revision History
Rev. Issue Date Description Page #
C 4/6/2006 Added LF Orderin
g
Information 10
D 1/24/2008 Removed DIP Orderin
g
Information. -
E 3/18/2008 Removed reference to "AV". -
