8T49N105A-008NLGI

Overview

The IDT8T49N105I is a FemtoClock NG Universal Frequency Translator and Synthesizer featuring low phase noise and alarm monitoring functions. It generates output frequencies from 0.98MHz to 312.5MHz, with most frequencies supported up to 1,300MHz. The device supports three operating modes: Frequency Synthesizer, High-Bandwidth Frequency Translator, and Low-Bandwidth Frequency Translator. Input references range from 8kHz to 710MHz, while crystal inputs operate between 16MHz and 40MHz. It provides a single differential output pair (Q, nQ) programmable as LVDS or LVPECL. Power supplies include VCC/VCCA/VCCO at 3.3V/3.3V/3.3V, 3.3V/3.3V/2.5V, or 2.5V/2.5V/2.5V. The component operates within an ambient temperature range of -40°C to 85°C.

Feature Summary

• Fourth-generation FemtoClock NG technology with zero ppm frequency translation capability
• Single differential input supporting LVPECL, LVDS, LVHSTL, and HCSL types
• Two factory-programmed One-Time Programmable (OTP) configurations for power-up defaults
• RMS phase jitter of 439fs (typical) at 155.52MHz in Low Bandwidth Mode

Applications

• Networking and communications applications requiring jitter attenuation
• PCI Express and computing systems utilizing high-bandwidth frequency translation
• General purpose clock generation from fundamental mode crystals

Procurement Notes

Verify the specific ordering suffix against the manufacturer's current documentation to confirm package type and lead-free status. Confirm that the device meets RoHS 6 compliance requirements for your assembly process. Check for any Product Change Notices (PCN) related to manufacturing sites or materials. Ensure the I2C address configuration via S_A0 and S_A1 pins aligns with system bus constraints.

Selection Notes

Select this component when a single differential output is sufficient for the design. Choose the appropriate supply voltage combination (3.3V or 2.5V) based on the target interface levels for LVPECL or LVDS outputs. Utilize the CONFIG pin or register to select between two distinct factory-programmed default states if multiple clock configurations are needed without I2C intervention during operation.

Part Context

This device belongs to the IDT8T49N105I series within the FemtoClock NG family. It serves as a general-purpose Universal Frequency Translator designed for networking and communications. The part integrates alarm monitoring and holdover capabilities to maintain signal integrity during reference loss.

Replacement Considerations

Consult Renesas Electronics for verified cross-reference part numbers. Verify compatibility of I2C register maps and pin assignments before substitution.

FAQ

How many factory-programmed configurations does the IDT8T49N105I support?

The device supports two factory-programmed default configurations stored in One-Time Programmable (OTP) memory, selectable via the CONFIG pin or register.

What is the maximum output frequency supported by the IDT8T49N105I?

The device can generate output frequencies up to 1,300MHz, although full support applies to most frequencies in the 312.5MHz to 1,300MHz range.

Can the output type be changed after power-up?

Yes, the output type (LVDS or LVPECL) can be reconfigured via the I2C interface after power-up, although settings must be rewritten upon each power cycle.