MAX9451EHJ2T

Overview

The MAX9451EHJ2T is a high-precision clock generator with an integrated Voltage-Controlled Crystal Oscillator (VCXO), manufactured by Microchip Technology. It provides two differential outputs in the HSTL format, operating within a frequency range of 15MHz to 160MHz. The device accepts reference inputs from 8kHz to 500MHz via LVPECL, LVDS, or LVCMOS interfaces. Key electrical parameters include a supply voltage of 2.4V to 3.6V for digital/analog sections and 1.4V to 1.6V for VDDQ, with output jitter less than 0.8ps RMS (12kHz–20MHz). It features a PLL lock range exceeding ±60ppm and operates between -40°C and +85°C in a 32-TQFP package.

Feature Summary

• Integrated VCXO eliminates external components for cost-effective high-precision clock generation.
• Dual differential outputs configured for HSTL signaling standards.
• Input clock monitor with hitless switching capability between two reference sources.
• I2C or SPI programmable interface for flexible input/output frequency selection.

Applications

• SONET/SDH systems
• 10 Gigabit Ethernet routers and switches
• 3G cellular phone base stations
• General jitter attenuation for high-speed ADCs and DACs

Procurement Notes

Verify the '2T' suffix against official documentation to confirm tape-and-reel packaging specifications. Confirm that the specific ordering code matches the HSTL output variant, as other suffixes may indicate different output formats like LVPECL or LVDS. Ensure compatibility with the required VDDQ supply voltage range of 1.4V to 1.6V for this specific model.

Selection Notes

Select the MAX9451EHJ2T when HSTL differential outputs are required for the target system. Compare against MAX9450 (LVPECL) and MAX9452 (LVDS) if alternative signaling standards are needed. Ensure the application requires an integrated VCXO solution to reduce board space and component count. Verify that the input reference frequencies fall within the 8kHz to 500MHz range.

Part Context

This component belongs to the MAX9450/MAX9451/MAX9452 family of high-precision clock generators. While all three share identical internal architectures and pinouts, they differ exclusively in their output buffer configurations. The MAX9451 specifically utilizes HSTL outputs, distinguishing it from the LVPECL-based MAX9450 and the LVDS-based MAX9452.

Replacement Considerations

Direct functional replacements within the same package and feature set include the MAX9450EHJ (LVPECL outputs) and MAX9452EHJ (LVDS outputs). Substitution requires verifying that the receiving circuitry supports the alternative output signaling standard (LVPECL or LVDS) instead of HSTL.