CYI9531OXC

Clock Generators, PLLs, Frequency Synthesizers Overview

The CYI9531OXC is a PCIX I/O System Clock Generator with EMI control features, manufactured by Silicon Laboratories. It accepts an input clock frequency of 25 MHz to 33 MHz and provides output frequencies of XINx1, XINx2, XINx3, and XINx4 through a dedicated bank of five clocks plus one REF XIN output. The device operates on a 3.3V supply (3.135V to 3.465V) and features spread spectrum clock generation for EMI reduction. Key electrical specifications include output jitter less than 175 ps, skew under 250 ps within the output bank, and a duty cycle of 50% (±5%). It utilizes an SMBus interface for individual clock disabling and configuration.

Clock Generators, PLLs, Frequency Synthesizers Feature Summary

• Generates multiple output frequencies (XINx1, x2, x3, x4) from a single 25-33 MHz input source.
• Includes Spread Spectrum Clock Generation (SSCG) to reduce electromagnetic interference.
• Features dedicated clock buffer power pins (VDDP) to minimize noise, crosstalk, and jitter.
• Supports SMBus control for individual clock output enabling/disabling and frequency selection.

Clock Generators, PLLs, Frequency Synthesizers Applications

• PCIX I/O system clock generation
• PCI/PCI-X bus timing applications
• Systems requiring low-jitter clock distribution with EMI mitigation

Clock Generators, PLLs, Frequency Synthesizers Procurement Notes

Verify that the component matches the specific lead-free SSOP package variant indicated by the ordering suffix. Confirm the operating temperature range corresponds to commercial specifications (0°C to 70°C). Ensure compatibility with the required 3.3V power supply voltage and SMBus address configuration before integration.

Clock Generators, PLLs, Frequency Synthesizers Selection Notes

Select this device when a fixed-frequency clock generator with spread spectrum capabilities is required for PCI/PCI-X interfaces. It is suitable for designs needing independent control of up to five output clocks via SMBus. Consider the 28-pin SSOP package constraints and ensure adequate decoupling capacitors are placed near VDD and VDDP pins to maintain signal integrity.

Clock Generators, PLLs, Frequency Synthesizers Part Context

The CYI9531OXC is part of the C9531 family of clock generators produced by Silicon Laboratories. This specific part number denotes the lead-free version housed in a 28-lead Shrunk Small Outline Package (SSOP). It shares functional characteristics with other variants in the series, differing primarily in packaging and compliance attributes.

Clock Generators, PLLs, Frequency Synthesizers Replacement Considerations

Direct pin-compatible replacements within the same family include IMIC9531CY (standard SSOP) or IMIC9531CT (TSSOP), provided the package type change is acceptable. Verify that any substitute maintains the same SMBus protocol support and electrical specifications for 3.3V operation.