251M-40LF

Overview

The Renesas 251M-40LF is a VersaClock clock/frequency synthesizer IC designed for spread spectrum clock generation. It operates with a maximum frequency of 200MHz and utilizes an internal Phase-Locked Loop (PLL) to generate precise timing signals. The device accepts clock or crystal inputs and provides CMOS outputs in a single-channel configuration. It is housed in an 8-SOIC package, measuring 3.90mm in width, and supports a supply voltage range of 3.15V to 3.45V.

Feature Summary

• Integrates a PLL-based frequency synthesizer for generating stable clock signals
• Supports spread spectrum clock generation functionality
• Accepts both external clock and crystal input sources
• Delivers CMOS output signals for digital circuit synchronization

Applications

• System clock distribution in embedded electronics
• Timing reference generation for high-speed data interfaces
• Spread spectrum clocking to reduce electromagnetic interference (EMI)
• Synchronization circuits in industrial control systems

Procurement Notes

This component is officially classified as obsolete by the manufacturer. Procurement should focus on verifying the authenticity of remaining stock from authorized distributors. Buyers must confirm the specific revision level and packaging type, as legacy inventory may vary. Due to the end-of-life status, long-term supply continuity cannot be guaranteed through standard channels.

Selection Notes

Engineers selecting this part should prioritize designs that do not require future production scaling due to its obsolete status. The 200MHz maximum frequency and 3.15V-3.45V supply range define the operational boundaries. Designers must ensure compatibility with the 8-SOIC footprint and verify that the CMOS output drive strength meets the load requirements of the target application without additional buffering.

Part Context

The 251M-40LF belongs to the VersaClock family of clock generators produced by Renesas Electronics. This series is engineered to provide flexible timing solutions for various digital applications. As a specialized timing IC, it replaces discrete oscillator components by integrating synthesis and distribution capabilities into a single surface-mount package, simplifying board layout and reducing component count.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. Given the obsolete status, engineers should consult official Renesas replacement guides or contact technical support for qualified alternatives that match the 200MHz frequency and 8-SOIC package constraints.