AV9107C-11 Integrated Circuit Systems, Inc. Green PC CPU Frequency Generator General Description Features The AV9107C-11 offers a tiny footprint solution for generating a fixed system clock and a selectable CPU clock. The 16 selectable CPU frequencies provide all necessary clocks for 386, 486 and Pentium systems. • • • • • • In addition, the AV9107C-11 has one pin that, when forced low, will slow the CPU clock to 8 MHz. This feature is important in systems that have dynamic microprocessors. Dynamic microprocessors have a minimum operating speed, typically 8 MHz. In“green” PCs, the designer often wants to slow the CPU to its minimum operating speed to save power. The AV9107C-11 will smoothly slow the CPU to 8 MHz when the SLOWCLK pin goes low. The AV9107C-11 is fabricated using 0.8m CMOS technology. As a result, a 45/55 duty cycle can be achieved on the CPU clock and ±250ps worst case absolute jitter. 14-Pin SOIC • • • One pin slows CPU clock to 8 MHz Provides system clock and selectable CPU clock On-chip loop filter Runs up to 66 MHz at 3.3V Worst case cycle-to-cycle variation of 0.1% Smooth transition from one CPU frequency to another or to 8 MHz Lowest jitter, ±250ps absolute 16 internal frequencies for 386, 486 or Pentium systems Worst case duty cycle of 45/55 on CPU clock Functionality FS3 FS2 FS1 FS0 CLK1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 16.00 MHz 39.99 MHz 50.11 MHz 80.01 MHz 66.58 MHz 100.23 MHz 8.02 MHz 4.01 MHz 8.02 MHz 20.00 MHz 25.06 MHz 39.99 MHz 33.25 MHz 50.11 MHz 30.00 MHz 4.01 MHz Block Diagram AV 9107-11 RevA052197 PRODUCT REVIEW documents contain information on products in the formative or design phase of development. Characteristic data and other specifications are design goals. ICS reserves the right to change or discontinue these products without notice.