8T49N242-DDDNLGI8

Overview

The Renesas 8T49N242-DDDNLGI8 is a FemtoClock NG Universal Frequency Translator featuring one fractional-feedback PLL and four integer output dividers. It generates up to four independent output frequencies ranging from 8kHz to 1.0GHz (LVPECL/LVDS/HCSL) or 250MHz (LVCMOS). The device accepts two differential/single-ended input clocks (8kHz–875MHz) or a 10MHz–50MHz crystal reference. Key electrical parameters include a typical jitter of 0.35ps RMS (12kHz–20MHz), an initial holdover accuracy of ±50ppb, and programmable loop bandwidths from 0.2Hz to 6.4kHz. It operates on 2.5V or 3.3V supplies with -40°C to +85°C ambient temperature range.

Feature Summary

• Supports SDH/SONET and Synchronous Ethernet including all FEC rate conversions
• Generates four LVPECL/LVDS/HCSL or eight LVCMOS outputs
• Accepts up to two input clocks (8kHz–875MHz) plus crystal reference
• Programmable via I2C or external EEPROM with Timing Commander software support

Applications

• OTN or SONET/SDH equipment
• Gigabit and Terabit IP switches/routers including Synchronous Ethernet
• Video broadcast systems

Procurement Notes

Verify the specific ordering suffix 'DDD' against the manufacturer's official datasheet or factory documentation to confirm exact configuration details such as pre-programmed values or package variations. Confirm RoHS compliance status and lead times directly with authorized distributors or the manufacturer, as availability may vary.

Selection Notes

Select this component for applications requiring high-performance frequency synthesis with low jitter. Ensure the design supports the required output voltage levels (1.8V, 2.5V, or 3.3V) and utilizes the I2C interface for configuration. Consider the holdover requirements and loop bandwidth settings suitable for the target network synchronization standards.

Part Context

The 8T49N242 belongs to the FemtoClock NG family of universal frequency translators. It integrates a fractional-feedback PLL with multiple integer output dividers to provide flexible clock generation capabilities for high-speed digital interfaces and telecommunications infrastructure.

Replacement Considerations

Consult the manufacturer's replacement guide for verified substitutes. Generic cross-references should be validated against pinout, electrical specifications, and functional compatibility before implementation.