AD9877ABS

Overview

The AD9877ABS is a single-supply mixed-signal front end (MxFE) designed for MCNS-DOCSIS, DVB, and DAVIC-compliant set-top box and cable modem applications. It integrates a transmit path with a quadrature digital upconverter, interpolation filter, and 12-bit direct IF DAC operating at up to 232 MSPS. The receive path features a 12-bit ADC sampling at 33 MSPS and dual 8-bit IQ ADCs at 16.5 MSPS. A built-in DDS supports carrier frequencies up to 65 MHz. The device operates on a 3.3 V supply within the extended industrial temperature range of −40°C to +85°C.

Feature Summary

• Transmit Path: 12-bit TxDAC+ DAC with 232 MHz max sampling rate, quadrature digital upconverter, and selectable interpolation filters (12x or 16x).
• Receive Path: 12-bit IF ADC (33 MSPS) with >10 ENOBs at 70 MHz IF input; dual 8-bit IQ ADCs (16.5 MSPS).
• Direct Digital Synthesis: DDS capable of generating carrier frequencies up to 65 MHz with 26-bit frequency tuning resolution.
• Auxiliary Outputs: Two 12-bit Σ-Δ DACs for controlling external components such as VGAs or tuners.

Applications

• Cable modems
• Set-top boxes
• Wireless modems

Procurement Notes

Verify the specific suffix ABS against the manufacturer's current ordering guide to confirm package type and temperature grade. Confirm RoHS compliance status via the latest datasheet revision. Check for active manufacturing status as older MxFE revisions may have limited availability.

Selection Notes

Select this component for designs requiring a low-cost, single-supply solution for DOCSIS and DVB applications. Ensure the system clock requirements align with the internal PLL capabilities (up to 232 MHz). Verify that the host processor can interface with the SPORT serial port for register control and data handling.

Part Context

The AD9877 is part of Analog Devices' MxFE family, offering an integrated transmitter and receiver solution. It serves as a cost-effective alternative to discrete converter solutions, specifically targeting the cable modem and set-top box markets where space and power efficiency are critical constraints.

Replacement Considerations

The AD9873 is a pin-compatible predecessor. The AD9877 offers enhanced receive path undersampling performance compared to the AD9873. Verify pin compatibility and software register mapping when substituting between these two models.