ICS9158 Integrated Circuit Systems, Inc. Integrated Buffer and Motherboard Frequency Generator General Description Features The ICS9158 is a low cost frequency generator designed specifically for desktop and notebook PC applications. Eight high drive, skew-controlled copies of the CPU clock are available, eliminating the need for an external buffer. * * * * * * * * * Each high drive (50mA) output is capable of driving a 30pF load and has a typical duty cycle of 50/50. The CPU clock outputs are skew-controlled to within 250ps. The CPU clocks provide all necessary frequencies for 286, 386, 486 and Pentium systems, including support for the latest speeds of processors. 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 whenever slowing the CPU speeds. The ICS9158 makes a gradual transition between frequencies so that it meets the Intel cycle-to-cycle timing specification for 486 systems. 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. The ICS9158 is a third generation device, and uses ICS's patented analog CMOS Phase-Locked Loop technology for low phase jitter. ICS offers a broad family of frequency generators for motherboards, graphics and other applications, including cost effective versions with only one or two output clocks. Consult ICS for all of your clock generation needs. Block Diagram ICS9158RevB111595 * * * Eight skew-free, high drive CPU clock outputs Up to 100 MHz output at 5V 250ps skew between CPU and 2XCPU outputs Outputs can drive up to 30pF load 50mA output drivers Typical 50/50 duty cycle Compatible with 486 and Pentium CPUs Glitch-free start and stop clock option Optional power-down mode supports Energy Star ("green") PCs On-chip loop filter components Low power, high speed 0.8 CMOS technology 24-pin PDIP or SOIC package Clock Table (in MHz) Clock BUSCLK FDCLK REFCLK CPUCLK 2XCPUCLK ICS9158 16 24 14.318 4,8,30,20,25,33.3,40, or 50 8,16,60,40,50,66.6,80, or 100 ICS9158 CPU2 X14OUT X14IN VDD GND BUSCLK FDCLK CPU3 AGND OE CPU5 GND 1 2 3 4 5 6 7 8 9 10 11 12 ICS9158 Pin Configuration 24 23 22 21 20 19 18 17 16 15 14 13 S0 S1 CPU1 2XCPU VDD GND REFCLK CPU4 AVDD S2 CPU6 CPU7 24-Pin PDIP or SOIC Pin Descriptions for ICS9158 PIN NUMBER 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 PIN NAME CPU2 X14OUT X14IN VDD GND BUSCLK FDCLK CPU3 AGND OE CPU5 GND CPU7 CPU6 S2 AVDD CPU4 REFCLK GND VDD 2XCPU CPU1 S1 S0 TYPE Output Output Output Output Input Output Output Output Input Output Output Output Output Input Input DESCRIPTION CPU clock output. Crystal connection. Crystal connection. Digital POWER SUPPLY (+5V). Digital GROUND. 16 MHz clock output. 24 MHz floppy disk/combination I/O clock output. CPU clock output. ANALOG GROUND. OUTPUT ENABLE. Tristates all outputs when low.* CPU clock output. Digital GROUND. CPU clock output. CPU clock output. CPU clock frequency select 2.* ANALOG power supply (+5V). CPU clock output. 14.318 MHz clock output. Digital GROUND. Digital POWER SUPPLY (+5V). 2X CPU clock output. CPU clock output. CPU clock frequency select #1.* CPU clock frequency select #0.* * Input has internal pull-up to VDD. 2 ICS9158 Absolute Maximum Ratings AVDD, VDD referenced to GND . . . . . . . . . . . . . . . 7V Operating temperature under bias. . . . . . . . . . . . . . . . 0C to +70C Storage temperature . . . . . . . . . . . . . . . . . . . . . . . . . . -40C to +150C Voltage on I/O pins referenced to GND. . . . . . . . . . . GND -0.5V to VDD +0.5V Power dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5 Watts Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect product reliability. Electrical Characteristics at 5V VDD = +5V10%, TA=0C to 70C unless otherwise stated DC Characteristics PARAMETER SYMBOL Input Low Voltage Input High Voltage Input Low Current Input High Current Output Low Voltage Output High Voltage (Note 1) Output Low Current (Note 1) Output High Current (Note 1) Supply Current Output Frequency Change over Supply and Temperature (Note 1) Short Circuit Current (Note 1) Pull-up Resistor Value (Note 1) Input Capacitance (Note 1) Load Capacitance (Note 1) VIL VIH IIL IIH VOL VOH IOL IOH IDD FD ISC RPU Ci CL TEST CONDITIONS VIN=0V VIN=VDD IOL=20.0mA IOH=-30mA VOL=0.8V VOH=2.0V No load, 80 MHz With respect to typical frequency Each output clock Input pin Except X1, X2 Pins X1, X2 MIN TYP 2.0 -5 -5 2.4 45 25 0.25 3.5 65 -55 43 0.002 UNITS 0.8 V V A A V V mA mA mA % 5 5 0.4 -35 65 0.01 56 680 8 20 Note 1: Parameter is guaranteed by design and characterization. Not 100% tested in production. 3 MAX mA k pf pf ICS9158 Electrical Characteristics (continued) VDD = +5V10%, TA=0C to 70C unless otherwise stated AC Characteristics PARAMETER Output Rise time, 0.8 to 2.0V (Note 1) Rise time, 20% to 80% VDD (Note 1) Output Fall time, 2.0 to 0.8V (Note 1) Fall time, 80% to 20% VDD (Note 1) Duty cycle (Note 1) Jitter, one sigma (Note 1) Jitter, absolute (Note 1) Jitter, absolute (Note 1) Input Frequency Clock skew window between CPU and 2XCPU outputs (Note 1) Frequency Transition time (Note 1) SYMBOL TEST CONDITIONS MIN TYP MAX UNITS tr 30pF load - 1 2 ns tr 30pF load - 2.5 3 ns tf 30pF load - 0.5 1 ns tf 30pF load - 1.5 2 ns 40/60 48/52 0.5 2 60/40 2.0 5 500 dt tj1s tjab tjab fi Tsk 30pF load As compared with clock period 16-100 MHz clocks tft From 4 to 50 MHz -5 -500 14.318 100 250 % % % ps MHz ps 13 20 ms Note 1: Parameter is guaranteed by design and characterization. Not 100% tested in production. 4 ICS9158 ICS9158 CPU Clock Decoding Table (using 14.318 MHz input. All frequencies in MHz) CLOCK#2 CPU and 2XCPU S2 S1 S0 (Pin 15) (Pin 23) (Pin 24) 0 0 0 0 1 1 1 1 0 0 1 1 0 0 1 1 0 1 0 1 0 1 0 1 Peripheral Clocks 2XCPU (Pin 21) CPU 7.580 15.511 59.875 40.090 50.113 66.476 79.772* 100.226* 3.790 7.756 29.938 20.045 25.057 33.238 39.886* 50.113* BUSCLK (Pin 6) FDCLK (Pin 7) 16.002 24.003 Reference Clock REFCLK (Pin 18) 14.318 *5V only Frequency Transitions Stop Clock Feature (Optional Mask Version) A key feature of the ICS9158 is its ability to provide smooth, glitch-free frequency transitions on the CPU and 2XCPU clocks when the frequency select pins are changed. The frequency transition rate does not violate the Intel 486 or Pentium specification of less than 0.1% frequency change per clock period. The ICS9158 incorporates a unique stop clock feature compatible with static logic processors. When the stop clock pin goes low, the CPUCLK will go low after the next occurring falling edge. When STOPCLK again goes high, CPUCLK resumes on the next rising edge of the internal clock. This feature enables fast, glitch-free starts and stops of the CPUCLK and is useful in Energy Start motherboard applications. Please contact ICS marketing for more details. Using an Input Clock as a Reference The ICS9158 is designed to accept a 14.318 MHz crystal as the input reference. With some external changes, it is possible to use a crystal oscillator or other clock sources. Please see application note AAN04 for details on driving the ICS9158 with a clock. CPUCLK STOPCLK 5 ICS9158 24-DIP Package Ordering Information ICS9158N-01 Example: ICS XXXX M -PPP Pattern Number (2 or 3 digit number for parts with ROM code patterns) Package Type N=DIP Device Type (consists of 3 or 4 digit numbers) Prefix ICS, AV=Standard Device; GSP=Genlock Device 6 ICS9158 LEAD COUNT DIMENSION L 24L 0.604 24 Lead SOIC Ordering Information ICS9158M-01 Example: ICS XXXX M -PPP Pattern Number (2 or 3 digit number for parts with ROM code patterns) Package Type M=SOIC Device Type (consists of 3 or 4 digit numbers) Prefix ICS, AV=Standard Device; GSP=Genlock Device 7