ICS9131 Datasheet | Integrated Circuit Systems

Integrated Circuit Systems, Inc. 32 Kh Z Motherboard Frequency Generator General Description The ICS9131 offers a tiny footprint solution for generating a selectable CPU clock from a 32.768 k Hz crystal. The device allows a variety of microprocessors to be clocked by changing the state of address lines FS0, FS1, and FS2. The ICS9131 is the ideal solution for replacing high speed oscillators and for reducing clock speeds to save power in puters. The device provides smooth, glitch-free frequency transitions so that the CPU can continue to operate during slow down or speed up. The rate of frequency change makes the ICS9131 patible with all 386DX, 386SX, 486DX, 486DXZ, 486SX and Pentium™ microprocessors. The ICS9131 is driven from a single 32.768 k Hz crystal. The only external ponents required are the crystal and a 10M ohm resistor. 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. Features - - - - - - - - - Single 32.768 k Hz crystal generates system clock and selectable CPU clock Generates CPU clocks from 8 MHz to 100 MHz. Operates from 3.3V or 5.0V supply Operates up to 66 MHz at 3.3V Separate VDD for 32 k Hz clock enables it to run from battery STOPCLK feature allows for a glitch-free turn-on and Pen-turn-off of the CPU clock to static processors Output enable tristates outputs 16-pin PDIP or SOIC package Frequency selects allow for a smooth transition of the CPUCLK Pin Configuration VDD32 Supply The ICS9131 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 and the main VDD at 0V. The frequencies and power-down options in the ICS9131 are mask programmable. Customer specific masks...