DOCSIS 3.1 High-Density SCQAM and OFDM Downstream Cable Modulator

Low Power, Fully Integrated, Symbols to RF Solution: 7mW/MHz in a 12mm X 18mm BGA

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The MAX5861 is an integrated, high-density, SCQAM and OFDM downstream cable modulator, digital up-converter (DUC) and RF digital-to-analog converter (RF-DAC). The MAX5861 is DOCSIS 3.1-compliant and is optimized for converged cable access platform (CCAP) hardware. The MAX5861 performs baseband I/Q symbols to RF up-conversion to digitally synthesize a selectable combination of SCQAM and OFDM blocks on a single RF port. A combination of up to six 192MHz blocks of SCQAM or OFDM channels can be powered on at any one time, where a block is defined as either 32 X 6MHz (or 24 X 8MHz) SCQAM channels or an OFDM channel (up to 192MHz wide). The MAX5861 features three differential time-multiplexed input data ports that support LVDS or SSTL 1.2/1.5 in DDR mode.

The MAX5861 SCQAM input port A accepts 10-bit Forward Error Correction (FEC)-encoded data for up to 160 (6MHz) individually programmable channels. The SCQAM path performs QAM mapping, root raised cosine (RRC) pulse shaping, and resampling, compliant with ITU-T J.83 Annex A, B, and C. This port also supports 1024-QAM with the use of an offset bias bit. Up to four channels can be operated in RRC filter bypass mode at up to 2.5Msym/s for legacy communications to older generation devices.

Each of two available 9-bit OFDM ports, B or C, support up to three 12-bit OFDM IFFT-processing channels. Each IFFT-processing channel supports OFDM blocks of up to 192MHz bandwidth with selectable 4k or 8k subcarriers and up to 4096-QAM modulation options. Each of the two OFDM ports also allow bypassing of the IFFT processing with a single 18-bit I/Q data path to support user-defined modulation at up to 192MHz bandwidth.

A cascade of interpolation filters, complex modulators, channel combiners and Direct Digital Frequency Synthesizers (DDFS) up-convert the SCQAM and/or OFDM signals with full frequency agility from 43MHz to 1218MHz. The up-converted spectrum is fed to a Digital Pre-Distortion (DPD) block to compensate for distortion performance limitations in the DAC and external output amplifiers.
MAX5861: Simplified Block Diagram MAX5861: Simplified Block Diagram Enlarge+

Key Features

  • High-Density Cable Downstream Modulator
    • Combine Up to Six 192MHz Blocks of 32 x 6MHz SCQAM Channels and DOCSIS 3.1 OFDM Channels
    • Integrated 14-Bit 4.9152Gsps RF-DAC
  • Highly Flexible and Configurable
    • ITU-T J.83 Annex A, B, and C SCQAM Channels
    • IFFT Processing D3.1 OFDM Channels
    • LVDS or SSTL 1.2/1.5 DDR Data Ports
    • One 10-Bit SCQAM Port with 160-Channel Capacity
    • Two 9-Bit OFDM Ports with 6 OFDM-Channel Capacity
    • Channel Bandwidths:
    • 1MHz to 8MHz SCQAM
    • 24MHz/48MHz/96MHz/192MHz OFDM
    • 192MHz IFFT Bypass Mode
    • Full SCQAM Agility within 192MHz Block
    • Block Agility within 1218MHz Output Bandwidth
  • Additional Features Ease RF Design
    • Programmable Digital Predistortion
    • High Output Power: 9dBm (Peak CW)
  • Low-Power, Compact Solution
    • 5.9W with 128 SCQAMs + 2 OFDM Channels
    • Operating Temperature Range TA = -40°C to TJ = +110°C
    • 12mm x 18mm, 308-Ball LFBGA


  • CCAP, Edge QAM, CMTS
  • DOCSIS 3.0/3.1 and DVB-C/C2
  • Multi-Dweller Units (MDU), Mini-Headends
  • Remote PHY, Coax Media Converters

See parametric specs for Modulators and Digital Upconverters (3)

Part NumberResolution
Update Rate
Modulation ModeCapacity RangeCapacity TypeInput InterfaceOutput InterfacefOUT
(mm x mm)
Oper. Temp.
@ Max Capacity
MAX5861 144915
Differential Analog RF1218Integrated5900
12 x 18-40 to +85

Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

MAX5861EVKIT: Evaluation Kit for the MAX5861
Request Reliability Report for: MAX5861 
Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C   Material Composition  

Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

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