ICD2028 Datasheet | Cypress

Features - Eight independent clock outputs handle all clocking requirements for personal puter motherboards - CPU clock frequency range: 10 MHz to 100 MHz with user-defined duty cycle - Four user-configurable outputs - Skew-free CPU clock, CPU clock ÷2, and buffered CPU clock options on configurable outputs - Ideally suited for desktop PCs - Phase-locked loop oscillator input derived from single 14.31818 MHz crystal - Sophisticated internal loop-filter requires no external ponents - Battery input maintains 32.768 k Hz clock during power-down - Three-state oscillator control disables outputs for test purposes - 5V operation - Low-power, high-speed CMOS technology - Available in 20-pin SOIC package configuration Functional Description A modern personal puter motherboard often requires as many as seven different crystal can oscillators. The System Logic family of frequency synthesis parts from Cypress/IC Designs replaces the large number of oscillators required to build such multi-function motherboards. These parts synthesize all the required frequencies in a single monolithic device, thus lowering manufacturing costs and significantly reducing the printed circuit board space required. The ICD2028 is a second-generation PC Motherboard Clock Generator built on the foundation of the industry-standard and most widely-used ICD2023. The ICD2028 offers most of the features of the ICD2023, as well as some important enhancements: - An additional VCO - An additional clock output - Four customer-configured outputs which can be configured to have - A skew-free divided-by-two CPU clock - An additional skew-free CPU clock - User-definable CPUCLK output duty cycle Because today’s desktop PCs must support a myriad of new requirements, and each pany’s implementation tends to be unique, the most important new feature of the ICD2028 is its ability to tailor four of the outputs to the individual needs of today’s system logic design engineer, and to configure the CPUCLK duty cycle for...