8T49N241-999NLGI#

Overview

The Renesas 8T49N241-999NLGI is a FemtoClock NG Universal Frequency Translator (UFT) IC. It features one fractional-feedback PLL and one integer plus three fractional output dividers, generating up to four independent output frequencies ranging from 8kHz to 1.0GHz (differential) or 250MHz (LVCMOS). The device accepts two differential inputs (LVPECL, LVDS, LVHSTL, HCSL, LVCMOS) and supports boot configuration from an external I²C EEPROM. It provides jitter attenuation meeting 10G to 25G Ethernet limits with 0.35ps RMS jitter (12kHz–20MHz) and operates on a 2.375V to 3.465V supply within a -40°C to +85°C temperature range.

Feature Summary

• Generates up to four independent output frequencies using one integer and three fractional dividers
• Supports boot configuration from external I²C EEPROM for flexible system integration
• Provides 0.35ps RMS jitter performance including spurs in the 12kHz to 20MHz bandwidth
• Features auto/manual input clock selection with hitless switching capabilities

Applications

• 10G/40G/100G SONET/SDH and Ethernet network line cards
• GbE/10GbE/100GbE Synchronous Ethernet applications
• Wireless base station baseband units
• Carrier Ethernet switches and OTN equipment

Procurement Notes

Verify component status as the 8T49N241 series has been transferred to SiTime. Confirm availability through official channels until end of 2026. Check datasheet addendums for specific package and marking changes. Ensure compatibility with existing I²C EEPROM configurations during procurement planning.

Selection Notes

Select this model when booting from external EEPROM is required, distinguishing it from the -998 variant which boots from OTP. Verify that the application requires fractional division for precise frequency generation up to 1GHz. Confirm input signal levels match supported standards such as LVDS or LVPECL. Evaluate thermal requirements against the specified -40°C to +85°C operating range.

Part Context

This component belongs to the FemtoClock NG family of universal frequency translators. The product line has been acquired by SiTime, with Renesas supporting existing orders until the end of 2026. New designs should consult SiTime for future support and documentation updates regarding the 8T49N241 series.

Replacement Considerations

Publicly listed similar replacements include the 8T49N241-994NLGI, 8T49N241-998NLGI, and 8T49N242-998NLGI8. Verify functional equivalence regarding boot source and output divider configuration before substitution.