MAX3665EUA

Overview

The MAX3665EUA is a low-power transimpedance preamplifier designed for 622Mbps SDH/SONET applications. It operates from a single +3.3V or +5.0V supply, consuming only 70mW at VCC = 3.3V. The device converts small photodiode currents to measurable differential voltages with an overall transimpedance gain of nominally 8kΩ. It features a DC cancellation circuit that provides true differential output swing over a wide range of input current levels, reducing pulse-width distortion. The differential outputs are back-terminated with 50Ω per side and can drive a 100Ω load. The MAX3665 offers a typical bandwidth of 470MHz and an input-referred noise of 55nARMS.

Feature Summary

• Single-supply operation compatible with +3.3V or +5.0V power rails
• Integrated DC cancellation loop minimizes pulse-width distortion across varying input signal levels
• Differential outputs provide back-termination and drive standard 100Ω loads directly
• Optimized for ultra-low power consumption in high-speed optical receiver designs

Applications

• SDH/SONET Receivers
• PIN Photodiode Preamplifiers and Receivers
• Regenerators for SDH/SONET

Procurement Notes

Verify the specific suffix 'EUA' corresponds to the commercial temperature range (-40°C to +85°C) and the 8-pin µMAX package configuration. Confirm RoHS compliance status as indicated by the '+' suffix in ordering information. Ensure compatibility with existing board layouts regarding the specific pinout and thermal dissipation requirements for the µMAX footprint.

Selection Notes

Select this component when designing fiber optic modules requiring optimized bandwidth and noise characteristics specifically for 622Mbps data rates. Consider its integration with clock recovery ICs like the MAX3676 for complete receiver solutions. Evaluate the trade-off between input capacitance and bandwidth, noting the device is optimized for approximately 0.5pF source capacitance to achieve minimum noise performance.

Part Context

The MAX3665 belongs to Maxim Integrated's family of transimpedance amplifiers tailored for telecommunications. It serves as a critical front-end stage in optical receivers, bridging the gap between photodetectors and limiting amplifiers. Its design focuses on minimizing jitter and maintaining signal integrity in high-speed serial data links common in SONET/SDH networks.

Replacement Considerations

No direct public substitute part numbers are confirmed in the provided documentation.