8T49N105A-006NLGI8

Overview

The IDT8T49N105I is a FemtoClock NG Universal Frequency Translator featuring fourth-generation PLL technology. It generates output frequencies from 0.98MHz to 1300MHz using a single differential input (LVPECL, LVDS, LVHSTL, HCSL) or a 16MHz-40MHz crystal. The device supports three modes: Frequency Synthesizer, High-Bandwidth Translator, and Low-Bandwidth Translator with jitter attenuation. It provides one programmable LVPECL or LVDS output pair. Key electrical parameters include an input frequency range of 8kHz-710MHz, core voltage options of 2.5V or 3.3V, and typical RMS phase jitter of 439fs at 155.52MHz in low-bandwidth mode. It operates from -40°C to 85°C in a 40-lead VFQFN package.

Feature Summary

• Single differential input supporting LVPECL, LVDS, LVHSTL, and HCSL levels
• Three operating modes: Frequency Synthesizer, High-Bandwidth, and Low-Bandwidth Frequency Translator
• Two factory-programmable power-up configurations stored in OTP memory
• RMS phase jitter of 439fs (typical) at 155.52MHz in Low Bandwidth Mode

Applications

• Networking and communications line cards
• PCI Express computing applications
• General purpose clock translation

Procurement Notes

Verify the specific ordering suffix for the 8T49N105A-006NLGI8 variant against official Renesas/IDT documentation to confirm pinout and configuration details. Ensure compatibility with the 40-lead VFQFN 6mm x 6mm package dimensions during PCB layout. Confirm that the required I2C address bits match the hardware strap settings on S_A0 and S_A1 pins.

Selection Notes

Select this component when a single output channel is sufficient for frequency synthesis or translation tasks. Choose the Low-Bandwidth mode if significant jitter attenuation from a noisy input source is required, utilizing an external crystal. Use the High-Bandwidth mode for tracking spread-spectrum modulation or when jitter attenuation is not needed. Ensure the desired output frequency falls within the supported divider ranges defined in Table 3 of the datasheet.

Part Context

This device belongs to the FemtoClock NG Universal Frequency Translator family, which includes multi-output variants such as the 8T49N028 (8 outputs), 8T49N241 (4 outputs), and 8T49N445 (4 independent PLLs). Unlike these higher-channel-count devices, the 8T49N105I is optimized for cost-sensitive applications requiring only one differential output pair while maintaining low phase noise performance.

Replacement Considerations

Direct replacements within the same package and functionality are limited due to the unique single-output configuration. Consider the 8T49N028 if additional output channels are acceptable, though it requires a different package and pinout. Verify register compatibility if migrating between different UFT family members.