ADN2855ACPZ-R7

Overview

The ADN2855ACPZ-R7 is a burst mode clock and data recovery IC designed for GPON, BPON, and GEPON optical line terminal receivers. It supports data rates of 155.52 Mbps, 622.08 Mbps, 1244.16 Mbps, and 1250.00 Mbps. The device features a patented dual-loop architecture with CML differential input and LVDS parallel or serial output. Operating on a single 3.3 V supply (3.0 V to 3.6 V), it consumes 670 mW in serial mode and 825 mW in deserializer mode. It acquires lock within 12 bits at higher speeds and operates from -40°C to +85°C in a 32-lead LFCSP package.

Feature Summary

• Burst Mode Operation: Acquires phase lock within 12 UI at 1250/1244/622 Mbps and 6 UI at 155.52 Mbps using preamble detection.
• Dual-Loop Architecture: Combines frequency-locked loop (FLL) and delay/phase-locked loop (D/PLL) for rapid acquisition.
• Flexible Output: Provides 4-bit parallel LVDS outputs or serial LVDS output with full/half-rate clock options.
• I2C Control: Configurable via I2C interface for data rate selection, output modes, and reference clock locking.

Applications

• GPON/BPON/GEPON Optical Line Terminal (OLT) Receivers
• Passive Optical Networks (PON)
• Multirate Optical Transceivers

Procurement Notes

Verify the specific suffix R7 corresponds to the reel packaging configuration required for automated assembly. Confirm that the 32-LFCSP-VQ (5x5) package dimensions align with the target PCB footprint. Ensure the design supports the necessary I2C bus addressing and reference clock requirements specified in the datasheet.

Selection Notes

Select this component for applications requiring burst-mode recovery in PON systems. Ensure the system provides a reference clock locked to the incoming data rate. Verify that the FPGA or ASIC interface supports the selected LVDS output mode (parallel nibble or serial). Check thermal constraints as the device dissipates up to 825 mW.

Part Context

This part belongs to Analog Devices' specialized timing and clock recovery family. It is specifically engineered for downstream processing in passive optical networks where variable data rates and bursty traffic patterns are standard. The ADN2855 complements other OLT components by handling the critical task of retiming upstream bursts.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. Evaluate pin-compatible alternatives only if they support identical burst mode acquisition times and LVDS output specifications.