251MILF

Overview

The Renesas 251MILF is a field-programmable clock synthesizer belonging to the VersaClock series. It functions as a spread spectrum clock generator with a maximum output frequency of 200 MHz. The device utilizes a Phase-Locked Loop (PLL) architecture and accepts input from a crystal or clock signal ranging from 3 to 150 MHz. It operates on a single 3.3 V supply, specifically within the 3.15 V to 3.45 V range. The component provides one CMOS output channel in an 8-SOIC package. Designed for electromagnetic interference reduction, it supports configurable spread spectrum modulation.

Feature Summary

• Field-programmable via One-Time Programmable (OTP) ROM using four selectable configuration registers.
• Generates output frequencies up to 200 MHz with integrated spread spectrum capabilities.
• Accepts input frequencies between 3 MHz and 150 MHz from crystals or clock sources.
• Includes power-down mode that tri-states outputs and disables PLL circuitry.

Applications

• Replacing multiple discrete crystals and oscillators to save board space.
• Reducing system electromagnetic interference (EMI) through spread spectrum techniques.
• Providing programmable clock signals for digital systems requiring specific frequency ratios.

Procurement Notes

The 251MILF is classified as obsolete with an End-of-Life date of March 30, 2025. Verification of current stock availability is required as the part may be out of production. Designers should confirm lead times and substitute options immediately due to the discontinued status.

Selection Notes

This component requires external configuration programming via IDT's VersaClock software before OTP writing. Ensure the input source matches the 3–150 MHz range and the load requirements align with the CMOS output drive levels. Verify that the 8-SOIC package dimensions fit the target PCB layout constraints.

Part Context

The 251MILF is part of the VersaClock family, originally developed by Integrated Device Technology (IDT) prior to its acquisition by Renesas Electronics. It serves as a low-cost solution for single-output clock generation. The 'LF' suffix indicates RoHS compliance, and the 'I' denotes industrial temperature rating.

Replacement Considerations

Public documentation identifies the 5P35021 VersaClock 3S Programmable Clock Generator as a replacement product for the 251 series.