Programmable PLL Clock Generator Triple 20-Pin SOIC

The CY2291 is a third-generation family of clock generators. The CY2291 is upwardly compatible with the industry standard ICD2023 and ICD2028 and continues their tradition by providing a high level of customizable features to meet the diverse clock synchoronous systems. All parts provide a highly configurable set of close for PC motherboard applications. Each of four configurable clock outputs (CLKA-CLKD) can be assigned 1 of 30 frequencies in any combination. Multiple outputs configured for the same or related frequencies have low (<500 ps) skew, in effect providing on-chip buffering for heavily loaded signals. The CY2291 can be configured for either 5 V or 3.3 V operation. The internal ROM tables use EPROM technology, allowing full customization of output frequencies. The reference oscillator has been designed for 10 MHz to 25 MHz crystals, providing additional flexibility. No external components are required with this crystal. Alternatively, an external reference clock of frequency between 1 MHZ to 30 MHz can be used. Customers using the 32 kHz oscillator must connect a 10-M? resistor in parallel with the 32 kHz crystal.

• Three integrated phase-locked loops
• EPROM programmability
• Factory-programmable (CY2291) or field-programmable (CY2291F) device options
• Low-skew, low-jitter, high-accuracy outputs
• Power-management options (Shutdown, OE, Suspend)
• Frequency select option
• Smooth slewing on CPUCLK
• Configurable 3.3 V or 5 V operation
• 20-pin SOIC Package