Analog Devices Inc./Maxim Integrated DS33W41+

Overview

DS33W41+ from Maxim Integrated is a single-port Ethernet-over-PDH mapping device with four TDM serial ports and one integrated voice port, supporting GFP-F/HDLC/X.86 encapsulation, VCAT/LCAS link aggregation, and IEEE 802.3 10/100/1000Mbps MAC interface (GMII/MII/RMII). It enables Ethernet delivery over T1/E1/J1, T3/E3, and xDSL infrastructure in carrier-grade access networks.

For engineers reviewing the DS33W41+ datasheet, DS33W41+ pinout, DS33W41+ application, or DS33W41+ equivalent, key selection criteria include its 4× TDM + 1× voice port configuration, 256-ball CSBGA package, support for differential delay up to 200ms, external DDR SDRAM buffering, and QoS features including VLAN, Q-in-Q, 802.1p, and DSCP.

Technical Context

The DS33W41+ implements store-and-forward frame processing with wire-speed bridging and traffic conditioning. Its dual-interface processor bus supports parallel 8-bit and SPI microcontroller connections, while the Ethernet MAC layer provides autonegotiation, flow control, and programmable classification/policing via CIR/CBS.

VCAT/LCAS functionality enables dynamic inverse multiplexing across up to 16 TDM links with LCAS hitless bandwidth adjustment. The voice port operates in μ-law/A-law PCM mode and interfaces directly with external codecs-distinctive to the W-series variants (DS33W41+/DS33W11+) within the family.

Key Specifications

Pinout & Package

The DS33W41+ is housed in a 17mm × 17mm, 256-ball fine-pitch CSP (CSBGA) package with 0.8mm ball pitch, designed for high-density carrier-grade line card layouts and thermal reliability under continuous operation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Ethernet-over-PDH mapping applications.

Compared with DS33X41+ and DS33W11+, the DS33W41+ uniquely balances 4× TDM capacity with integrated voice-making it optimal for mid-tier business access gateways where both bonded data and circuit-switched voice must coexist on shared TDM infrastructure.

Availability

DS33W41+ is available at Aetrix Electronics and suitable for bonded LAN service delivery, T1/E1-based LAN extension, and integrated voice+data access gateway applications requiring stable component supply across extended product lifecycles.

Supply support for DS33W41+ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated (now part of Analog Devices) is a U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for communications, industrial, and automotive markets.

The DS33W41+ belongs to Maxim's Ethernet-over-PDH mapping product line, engineered specifically for carrier-class TDM-to-Ethernet transport in metro access and business service delivery platforms.

FAQ

What is the primary function of the DS33W41+ in an Ethernet-over-PDH system?

The DS33W41+ serves as a protocol mapper that converts IEEE 802.3 Ethernet frames into GFP-F, HDLC, cHDLC, or X.86 (LAPS) payloads for transport over synchronous TDM networks like T1/E1 or T3/E3. It also integrates a voice port for concurrent PCM voice handling, enabling combined data and voice service delivery on shared infrastructure. This makes DS33W41+ essential for eLINE and eLAN service provisioning in carrier access networks.

Does the DS33W41+ require an external PHY for Ethernet connectivity?

Yes, the DS33W41+ includes a MAC layer only (GMII/MII/RMII) and does not integrate a physical layer transceiver. An external 10/100/1000BASE-T PHY must be connected to the GMII/MII/RMII interface to drive copper or fiber media. The DS33W41+ manages frame encapsulation, QoS, bridging, and TDM mapping-but relies on external PHYs for signal-level compliance with IEEE 802.3 standards.

How does the DS33W41+ handle voice traffic alongside Ethernet data?

The DS33W41+ includes a dedicated 8-bit PCM voice port (VPCM_IN/VPCM_OUT) operating at standard ITU-T G.711 μ-law or A-law rates, synchronized to VCLK. It interfaces directly with external codecs-bypassing the Ethernet MAC and TDM encapsulation paths-allowing simultaneous real-time voice transport and packetized data over the same TDM infrastructure. This dual-path architecture is exclusive to the W-series (DS33W41+/DS33W11+) in the family.

What memory interface does the DS33W41+ support, and why is it required?

The DS33W41+ integrates a DDR SDRAM controller supporting 256Mb, 125MHz external DDR memory. This memory is mandatory for frame buffering, traffic shaping (CIR/CBS policing), and QoS queue management. Without it, the device cannot perform store-and-forward operations, maintain latency-sensitive voice buffers, or enforce bandwidth guarantees-rendering DS33W41+ nonfunctional in production systems.

Is the DS33W41+ pin-compatible with other devices in the DS33X/W series?

The DS33W41+ shares the same 256-ball CSBGA package and mechanical footprint with DS33X162+, DS33X161+, DS33X82+, DS33X81+, DS33X42+, and DS33X41+, but is not fully pin-compatible due to dedicated voice port signals (VPCM_IN/VPCM_OUT, VCLK, VFS) absent in X-series variants. These pins are NC or repurposed in non-W parts, requiring board-level redesign for substitution-even though package dimensions and most I/Os align.