LMK61E2-SIAR

Overview

The LMK61E2-SIAR is an ultra-low jitter fully programmable oscillator from Texas Instruments, featuring a PLLatinum™ fractional-N frequency synthesizer and integrated VCO. It supports output configurations of LVPECL, LVDS, or HCSL. The device includes on-chip EEPROM for self-startup at factory-programmed settings, such as 156.25MHz LVPECL. It operates within a supply voltage range of 3.135V to 3.465V, with a maximum output frequency of 900 MHz to 1 GHz. Key electrical parameters include a phase jitter of 90 fs, operating current of 152 mA to 162 mA, and duty cycle of 55%. It functions in temperatures from -40°C to +85°C.

Feature Summary

• Integrates a PLLatinum™ fractional-N frequency synthesizer with an internal VCO for precise clock generation.
• Features on-chip EEPROM for self-startup capabilities using factory-programmed default settings.
• Supports complete system-in-package programming via I²C serial interface for registers and EEPROM.
• Provides internal power regulation to ensure high power supply ripple rejection ratio (PSRR).

Applications

• Generating common reference clocks for high-speed data converters
• System timing margin testing and design verification tests (DVT)
• Standard compliance testing requiring precise frequency stability
• Ultra-low jitter clock distribution in telecommunications infrastructure

Procurement Notes

Verify the specific suffix 'SIAR' against the manufacturer's official documentation to confirm the exact factory-programmed frequency and output format. Ensure that the required startup configuration matches the pre-burned EEPROM values, as these cannot be altered after manufacturing without reprogramming the entire device family if supported. Confirm package compatibility with the 8-QFM footprint.

Selection Notes

Select this component when ultra-low jitter performance is critical for system integrity. The integrated VCO and PLLatinum™ architecture reduce external component count compared to discrete solutions. Consider the I²C programmability for flexibility in design validation, while noting that the EEPROM content is fixed at the factory for the specific part number variant. Evaluate the PSRR benefits for simplifying power delivery network design.

Part Context

The LMK61E2 belongs to Texas Instruments' LMK61xx series of ultra-low jitter oscillators. This series is designed to replace traditional crystal oscillator solutions by offering programmable frequencies and lower jitter through advanced synthesis technology. The LMK61E2 specifically targets applications requiring high precision and low phase noise, leveraging silicon-based VCXO technology for compact form factors.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided source material.