ICS9133X Datasheet | Integrated Circuit Systems

Integrated Circuit Systems, Inc. 32 k Hz Motherboard Frequency Generator General Description The ICS9133X is designed to generate clocks for all 286, 386, 486, Pentium and RISC-based motherboards, including laptops and notebook puters. The only external ponents required are a 32.768 k Hz crystal and decoupling capacitors. The device generates the 14.318 MHz system clock, eliminating the need for a 14.318 MHz crystal. High performance applications may require high speed clock termination ponents. The chip includes three independent clock generators plus the 32.768 k Hz reference clock to produce all necessary frequencies, including real time clock/DRAM refresh, master clock, CPU clock, twice CPUclock frequency, keyboard clock, floppy disk controller clock, serial munications clock and bus clocks. Different frequencies from clock #2 can be selected using the frequency select pins, but clock #1 will be at 14.318 MHz for all standard versions. Features - - - - - - - - - - - - - Single 32.768 k Hz crystal generates all PC motherboard clocks Cost-reduced version of popular ICS9132 Contains internal crystal load capacitors and feedback bias 3 independent clock generators Generates CPU clocks from 12.5 to 100 MHz Up to 7 output clocks Separate VDD for 32 k Hz clock Output enable tristates outputs Power-down options available Operates from 3.3V or 5.0V supply Operates up to 66 MHz at 3.3V Skew controlled 1X and 2X CPU clocks 20-pin PDIP or SOIC package VDD32 Supply The ICS9133X has a separate power supply for the 32.768 k Hz oscillator circuitry. This allows the 32 k Hz clock to run from a battery or other source while the main power to the chip is disconnected. The VDD32 supply is guaranteed to operate down to +2.0V, with the clock consuming less than 10µA at +3.3V with the main VDD at 0V. The frequencies and power-down options in the ICS9133X are mask programmable. Customer specific masks can be made and prototypes delivered within 6-8 weeks from...