MAX3670ETJ2T

Clock Generators, PLLs, Frequency Synthesizers Overview

The MAX3670ETJ2T is a low-jitter clock generator IC designed for system clock distribution and frequency synchronization in OC-48 and OC-192 SONET/SDH and WDM transmission systems. It integrates a phase/frequency detector, operational amplifier, prescaler dividers, and input/output buffers to form a PLL with an external VCO. The device operates from a single +3.3V or +5.0V supply, dissipating 150mW (typ) at 3.3V. Key electrical parameters include a maximum clock output frequency of 670MHz, intrinsic jitter less than 0.4psRMS, and PECL clock output interface. The operating temperature range spans from -40°C to +85°C.

Clock Generators, PLLs, Frequency Synthesizers Feature Summary

• Low intrinsic jitter (< 0.4psRMS) optimized for network applications
• Programmable PLL bandwidth adjustable from 15Hz to 20kHz via external components
• Supports reference clock frequencies of 155MHz, 622MHz, and up to 670MHz
• Includes loss-of-lock indicator and configurable gain-control logic

Clock Generators, PLLs, Frequency Synthesizers Applications

• OC-12 to OC-192 SONET/WDM transport systems
• Clock jitter clean-up and frequency synchronization
• Frequency conversion
• System clock distribution

Clock Generators, PLLs, Frequency Synthesizers Procurement Notes

Verify the specific package suffix against the manufacturer's ordering information to confirm lead-free status and physical dimensions. The ETJ2T designation corresponds to the Thin QFN-EP package variant. Ensure compatibility with the required supply voltage (+3.3V or +5.0V) and confirm that the external VCO selection aligns with the device's specified control voltage and gain transfer characteristics.

Clock Generators, PLLs, Frequency Synthesizers Selection Notes

Select this component when designing SONET/SDH or WDM systems requiring precise clock synchronization with ultra-low jitter. The internal op amp allows for flexible loop filter design, but an external VCO must be provided. Consider the PECL output interface requirements and ensure proper termination using fixed-impedance transmission lines. Verify that the external VCO's modulation bandwidth exceeds the set higher-order pole frequency to maintain stability.

Clock Generators, PLLs, Frequency Synthesizers Part Context

The MAX3670 is part of Maxim Integrated's (now Microchip Technology) portfolio of precision clock generators. It is specifically engineered for high-speed digital communication infrastructure, addressing the stringent timing requirements of optical networking standards. The device simplifies PLL design by integrating critical analog blocks, reducing the need for discrete components typically required for jitter attenuation in telecom equipment.

Clock Generators, PLLs, Frequency Synthesizers Replacement Considerations

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