251PMLF

Overview

The Renesas 251PMLF is a field-programmable clock synthesizer from the VersaClock series, manufactured by Integrated Device Technology (IDT) and now part of Renesas Electronics. It operates as a single-output spread spectrum clock generator with a maximum frequency of 200 MHz. The device utilizes an internal Phase-Locked Loop (PLL) to generate precise clock signals from input frequencies ranging from 3 MHz to 150 MHz or crystals between 5 MHz and 27 MHz. Powered by a 3.3 V supply (3.15V–3.45V range), it features CMOS outputs in an 8-SOIC package. The component supports configurable spread spectrum modulation to reduce electromagnetic interference and includes a power-down feature for energy efficiency.

Feature Summary

• Field-programmable architecture using One-Time Programmable (OTP) ROM with four selectable configuration registers.
• Spread spectrum clock generation capability to minimize system EMI.
• Supports output frequencies up to 200 MHz via PLL synthesis.
• Integrated power-down mode that tri-states outputs and disables the PLL.

Applications

• Replacing multiple discrete crystals and oscillators in embedded systems.
• Generating low-EMI clocks for high-speed digital circuits.
• System timing solutions where board space and cost reduction are critical.

Procurement Notes

The 251PMLF is classified as Obsolete with an End-of-Life (EOL) date of March 30, 2025. Verification of final availability through authorized channels is required before design finalization. Compliance with RoHS3 standards is confirmed. Moisture Sensitivity Level (MSL) is rated at Level 1, indicating unlimited floor life under standard conditions.

Selection Notes

Designers should account for the obsolete status when selecting this component for new products. Input crystal frequencies must fall within the 5 MHz to 27 MHz range, while external clock inputs can operate between 3 MHz and 150 MHz. The device requires a stable 3.3 V power supply. Configuration is achieved via IDT's VersaClock software prior to OTP programming.

Part Context

This component belongs to the VersaClock family of programmable clock generators. Originally developed by Integrated Device Technology (IDT), the product line was integrated into Renesas Electronics following their acquisition. The 251PMLF represents a legacy solution for single-output clock synthesis, succeeded by newer generations such as the 5P35021.

Replacement Considerations

Public documentation identifies the 5P35021 (VersaClock 3S) as a functional replacement. This alternative offers similar programmability and clock generation capabilities within the Renesas portfolio.