8T49N286A-998NLGI8

Overview

The Renesas 8T49N286A-998NLGI8 is a FemtoClock NG Octal Universal Frequency Translator featuring two independent fractional-feedback PLLs. It accepts up to four differential or single-ended input clocks and a crystal, generating eight output frequencies ranging from 8kHz to 1GHz. The device supports LVPECL, LVDS, HCSL, and LVCMOS output levels. Key electrical parameters include an operating voltage range of 2.375V to 3.465V, an initial holdover accuracy of ±50ppb, and typical jitter performance of <0.3ps RMS (12kHz to 20MHz). It operates within an ambient temperature range of -40°C to +85°C.

Feature Summary

• Generates up to eight output frequencies (8kHz to 1GHz) using two independent fractional-feedback PLLs with six integer and two fractional output dividers.
• Supports hitless reference switching between input clocks with automatic or manual selection and Loss of Signal (LOS) monitoring.
• Features programmable loop bandwidth settings for each PLL ranging from 1.4Hz to 360Hz.
• Includes individual phase delay settings for output alignment and support for gapped clock operation.

Applications

• OTN or SONET/SDH equipment line cards supporting FEC ratios.
• Gigabit and Terabit IP switches/routers including Synchronous Ethernet.
• Wireless base station baseband systems.
• 100G Ethernet applications.

Procurement Notes

Verify the specific ordering suffix against the manufacturer's current datasheet to confirm package type and temperature grade. Confirm availability status as supply conditions may vary. Ensure compatibility with required I2C or SPI programming interfaces and external EEPROM configurations if autonomous loading is needed.

Selection Notes

Select this component when multiple independent output frequencies are required from diverse input sources. Verify that the desired output voltage levels (LVPECL, LVDS, HCSL, or LVCMOS) match the system requirements. Check if the specific frequency translation ratios require exact conversion error handling or if standard fractional synthesis is sufficient.

Part Context

This part belongs to the Renesas FemtoClock NG family, designed for high-performance timing applications. It serves as a universal frequency translator capable of handling various synchronization standards including ITU-T G.709. The device integrates both jitter cleaning and frequency translation capabilities in a single 72-pin QFN package.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. Consult the manufacturer's obsolescence notices or cross-reference guides for potential alternatives if this specific variant is discontinued.

FAQ

What is the initial holdover accuracy of the 8T49N286A?

The device supports an initial holdover accuracy of ±50ppb for each PLL path when entering holdover state.

Can the 8T49N286A handle gapped clock inputs?

Yes, the device monitors all input clocks for Loss of Signal and supports configuration for gapped or ungapped clock operation.

How many independent PLLs does the device contain?

The 8T49N286A contains two independent fractional-feedback PLLs that can lock to different input clocks.