CYW255OXC

Overview

The CYW255OXC is a 200 MHz, 24-output clock buffer designed for PC applications supporting up to four DDR DIMMs or three SDRAM DIMMs. It features one input and 24 outputs, including dedicated pins for feedback and power management. The device operates with dual voltage supplies: VDD3.3_2.5 (3.135V to 3.465V) and VDD2.5 (2.375V to 2.625V). Key electrical parameters include a maximum propagation delay of 10 ns, output skew under 100 ps for DDR mode, and an operating temperature range of 0°C to +70°C. It utilizes a 48-pin SSOP package.

Feature Summary

• Supports up to 4 DDR DIMMs or 3 SDRAM DIMMs via configurable output modes
• Includes SMBus interface for individual output enable/disable control
• Low output skew (< 100 ps for DDR, < 150 ps for SDRAM)
• Dedicated pin for power management support (PWR_DWN#)

Applications

• Clock distribution for 4 unbuffered DDR DIMMs
• Clock distribution for 3 unbuffered standard SDRAM DIMMs
• Mixed configurations supporting 3 SDRAM and 2 DDR DIMMs

Procurement Notes

Verify the specific ordering suffix against the manufacturer's current documentation. The 'OXC' suffix indicates a lead-free, commercial-grade variant in a 48-pin SSOP package. Confirm availability status as component lifecycles may change. Ensure the procurement source provides valid traceability for the commercial temperature range specifications.

Selection Notes

Select this component when designing systems requiring a single-input, multi-output clock buffer for memory interfaces. Ensure the design accommodates the dual supply requirement: connect VDD3.3_2.5 to 3.3V for SDRAM mode or 2.5V for DDR-only mode. Verify that the PCB layout supports the required bypass capacitance and ferrite bead placement as detailed in the datasheet layout examples.

Part Context

The CYW255OXC is part of the W255 family of clock buffers originally developed by Silicon Laboratories (formerly Cypress Semiconductor). It serves as a high-speed buffer to distribute reference clocks from chipset synthesizers to multiple memory modules. The device is functionally compatible with other members of the W25x series, differing primarily in packaging and manufacturing revisions.

Replacement Considerations

Publicly confirmed substitute part numbers are not available in the provided documentation. Designers should consult the manufacturer's official cross-reference tools or contact technical support directly for verified replacement options.