9154A

The 9154A is a 0.8mm version of the industry leading 9154. Like the 9154, the 9154A is a low-cost frequency generator designed for general purpose PC and disk drive applications. However, because the 9154A uses 0.8mm technology and the latest phase-locked loop architecture, it offers performance advantages that enable the device to be sold into Pentium™ systems. The 9154A guarantees a 45/55 duty cycle over all frequencies. In addition, a worst case jitter of ±250ps is specified at Pentium frequencies. The CPU clock offers the unique feature of smooth, glitchfree transitions from one frequency to the next, making this the ideal device to use when slowing the CPU speed. The 9154A makes a gradual transition between frequencies so that it obeys the Intel cycle-to-cycle timing specifications for 486 and Pentium systems. The 9154A-42 and 9154A-43 devices offer features specifically for green PCs. The 9154A-42 and -43 have a single pin that, when pulled low, will smoothly slow the 2XCPU clock to 8 MHz. This is ideal for dynamic DX microprocessors. The 9154A-43 not only has the slow clock feature, but also offers a glitch-free stop clock for static SX microprocessors. The STOPCLK# pin, when pulled low, enables the 2XCPU clock to go low only after completing its last full cycle. The clock continues to run internally, and will be output again on the first full cycle immediately following stop clock disable. The simultaneous 2X and 1X CPU clocks offer controlled skew to within 500ps of each other (-42 only). 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. Consult ICS for all your clock generation needs.