MAX9451EHJ2

Overview

The MAX9451EHJ2 is a high-precision clock generator with an integrated VCXO, designed for SONET/SDH and Gigabit Ethernet systems. It features two differential inputs accepting LVPECL, LVDS, or LVCMOS signals within an 8kHz to 500MHz range. The device provides two differential HSTL outputs operating up to 160MHz. Configuration is managed via I²C or SPI interfaces. Key specifications include output jitter less than 0.8ps RMS (12kHz–20MHz) and phase noise attenuation exceeding -130dBc/Hz at 100kHz. It operates from a 2.4V to 3.6V supply in a 32-TQFP package.

Feature Summary

• Integrated VCXO eliminates external components for cost-effective high-precision clock generation
• Dual differential inputs support LVPECL, LVDS, and LVCMOS signaling formats
• Two differential HSTL outputs provide frequencies up to 160MHz
• Input clock monitor enables hitless switching between reference sources
• Internal holdover function maintains frequency within ±20ppm during input failure

Applications

• SONET/SDH Systems
• 10 Gigabit Network Routers and Switches
• 3G Cellular Phone Base Stations
• General Jitter Attenuation

Procurement Notes

Verify the specific suffix '2' against official NXP/Microchip documentation, as standard datasheets list 'MAX9451EHJ'. Confirm temperature grade and packaging details match project requirements. Ensure I2C/SPI address pins are configured correctly for system integration.

Selection Notes

Select this component when HSTL output signaling is required for Gigabit Ethernet or SONET applications. The integrated VCXO simplifies design by removing external oscillators. Ensure the loop filter bandwidth is set appropriately to balance phase transition smoothness and jitter performance.

Part Context

This part belongs to the MAX9450/MAX9451/MAX9452 family of high-precision clock generators. The MAX9451 variant specifically distinguishes itself by providing HSTL outputs, whereas the MAX9450 offers LVPECL and the MAX9452 provides LVDS outputs. All variants share the same pinout and core functionality.

Replacement Considerations

Direct replacements within the same family include MAX9450EHJ (LVPECL outputs) and MAX9452EHJ (LVDS outputs). Verify that the target application supports the specific output voltage levels of HSTL if substituting with other family members.