251PMILFT

Overview

The Renesas Electronics Corporation 251PMILFT is a field-programmable VersaClock synthesizer housed in an 8-SOIC package. It operates on a single 3.3V supply (3.15V to 3.45V) and supports input frequencies from 3 MHz to 150 MHz, generating output clocks up to 200 MHz. The device integrates a Phase-Locked Loop (PLL) and One-Time Programmable (OTP) ROM for configuration via four addressable registers. It features spread spectrum clock generation to reduce EMI and includes a power-down mode that tri-states outputs.

Feature Summary

• Field-programmable architecture with OTP ROM and four selectable configuration registers
• Spread spectrum modulation capability for system EMI reduction
• Single-output CMOS clock generation ranging from 314 kHz to 200 MHz
• Power-down feature that disables PLLs and tri-states outputs

Applications

• Replacing multiple discrete crystals and oscillators in embedded systems
• Generating precise clock signals for digital logic circuits
• EMI-sensitive applications requiring spread spectrum clocking techniques

Procurement Notes

The 251PMILFT is officially classified as obsolete by the manufacturer. Production End-of-Life (EOL) was announced for March 30, 2025. Current availability is restricted to existing stock or limited distributor inventory. Verification of component authenticity and physical condition is critical due to the end-of-life status and potential supply chain constraints.

Selection Notes

Designers should verify compatibility with the required input crystal frequency range of 5 MHz to 27 MHz and ensure the target application can accommodate the fixed 1:1 input-to-output ratio. The device requires a 3.3V supply voltage and operates within a temperature range of -40°C to +85°C. Consideration must be given to the irreversible nature of the OTP programming during the design phase.

Part Context

This component belongs to the Renesas VersaClock family of clock synthesizers. It serves as a low-cost solution for single-output clock generation, utilizing IDT's VersaClock software for initial PLL and output configuration before OTP programming. The part number alias ICS251PMILF indicates its lineage from Integrated Circuit Specialties, now part of Renesas.

Replacement Considerations

Public documentation identifies the 5P35021 (VersaClock 3S) as a functional replacement product offering programmable clock generation capabilities.