8T49N524NLG8

Overview

The IDT8T49N524I is a dual four-output programmable clock generator utilizing fourth-generation FemtoClock NG PLL technology. It features selectable LVPECL or LVDS outputs and supports fundamental mode crystals from 10MHz to 40MHz or external differential references (LVPECL, LVDS, HCSL) from 5MHz to 800MHz. The device generates two independent output frequencies ranging from 15.234MHz to 645MHz and 975MHz to 1290MHz using fractional output dividers. Typical RMS phase jitter is 0.282ps at 125MHz and 0.278ps at 156.25MHz (12kHz–20MHz). It operates on 2.5V or 3.3V supplies within a -40°C to 85°C temperature range in a 40-lead VFQFN package.

Feature Summary

• Dual independent clock generators with eight selectable LVPECL or LVDS outputs
• Fourth-generation FemtoClock NG PLL technology delivering sub-0.5ps RMS phase jitter
• Supports fundamental mode crystals (10MHz–40MHz) or external differential inputs (5MHz–800MHz)
• Factory-programmable default frequencies selectable via FSEL pins or I2C programming

Applications

• High-performance networking equipment requiring low-jitter clock synthesis
• Telecommunications systems utilizing synchronous Ethernet or SONET/SDH timing
• Test and measurement instruments demanding precise frequency generation

Procurement Notes

Verify the specific factory-programmed frequency configuration associated with the ordering suffix before procurement, as default frequencies are set at manufacture. Confirm power supply requirements (2.5V vs 3.3V) match the selected output voltage levels. Ensure I2C address selection via ADDR_SEL pin aligns with system bus constraints. Check for end-of-life status or alternative sourcing if long-term availability is required.

Selection Notes

Select this component when dual independent frequency sources with low jitter are required from a single reference. Choose based on whether LVPECL or LVDS output signaling is preferred, as both are configurable. Ensure the desired output frequencies fall within the supported ranges: 15.234MHz–645MHz or 975MHz–1290MHz. Verify that the input source matches either the internal crystal oscillator or external differential input capabilities.

Part Context

The IDT8T49N524I belongs to the FemtoClock NG family of programmable clock generators. It was originally manufactured by Integrated Device Technology (IDT), which was subsequently acquired by Renesas Electronics Corporation. The device provides flexible frequency synthesis solutions for applications requiring high precision and low phase noise across multiple output channels.

Replacement Considerations

Consult the official FemtoClock NG product ordering guide for direct replacements with different factory-programmed frequencies. Cross-reference with other dual-output FemtoClock NG models if pin compatibility or output count differs. Verify I2C register compatibility if migrating between similar devices within the same family.