ICS9159-20

Supply Voltage ....................................................... 7.0 V
Logic Inputs ........................... GND 0.5 V to V_DD +0.5 V
Ambient Operating Temperature .............. 0°C to +70°C
Storage Temperature ......................... 65°C to +150°C

Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. These ratings are stress 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.

The ICS9159-20 is a low-cost frequency generator designed specifically for SIS551X chip set and SIS6205 VGA controller. The integrated buffer minimizes skew. A 14.31818 MHz XTAL oscillator provides the reference clock to generate standard Pentium™ frequencies. The CPU clock makes gradual frequency transitions without violating the PLL timing of internal microprocessor clock multipliers.

Both synchronous and asynchronous bus designs of the ICS9159-20 are supported. For chip sets that require an early CPU clock, the buffers are driven by the CPU clock. In this configuration, the CPU clock becomes the early clock and the output of the uncommitted buffers become the bus synchronized bus clocks.