Analog Devices Inc./Maxim Integrated DS21352G

Overview

DS21352G from Maxim Integrated is a 3.3V T1 single-chip transceiver supporting DS1/ISDN-PRI/J1 line interface, long- and short-haul LIU operation, crystal-less jitter attenuation (32/128-bit selectable), and HDLC controller with 64-byte buffers configurable for FDL or DS0. It delivers -7.5dB/-15dB/-22.5dB CSU line build-outs and operates across 0–6000 ft cable lengths in telecom access equipment.

For engineers reviewing the DS21352G datasheet, DS21352G pinout, DS21352G application, or DS21352G equivalent, key selection considerations include its dual elastic store architecture for asynchronous backplane interfacing up to 8.192 MHz, IEEE 1149.1 JTAG boundary scan support, programmable in-band loop code generation/detection (1–8 bits), and compliance with ANSI T1.403-1995, ITU G.703/G.704/G.706/G.823, and I.431 standards.

Technical Context

The DS21352G integrates independent transmit and receive data paths with separate clock recovery, framing, and elastic store logic. Its framer locates D4 (SLC-96) and ESF multiframe boundaries, extracts/inserts robbed-bit signaling and FDL data, and monitors alarms including RCL, RLOS, RRA, and RAIS - all with state-change interrupt capability.

Line interface functionality decouples analog front-end from digital framer/formatter, enabling optical/HDSL/NRZ interface adaptation, bipolar data stream monitoring, and intentional error injection. The jitter attenuator is configurable in either path, and the 8.192 MHz clock output is synthesized and locked to RCLK.

Key Specifications

Pinout & Package

DS21352G is housed in a 100-pin LQFP package (14 mm × 14 mm) with 3.3V supply and mixed-signal pin segregation: analog receive (RRING/RTIP), analog transmit (TRING/TTIP), digital I/O (TDATA/RDATA), control (BTS/CS*/RD*/WR*), JTAG (JTMS/JTCLK/JTDI/JTDO), and system clocks (RSYSCLK/TSYSCLK/8MCLK).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar T1 transceiver applications.

Compared with DS21352G, DS21552LN offers voltage compatibility at the cost of higher power and level-shifting complexity, while DS21354LN delivers 4× channel density in identical packaging - making it optimal for carrier-grade line cards needing >1 T1 per ASIC slot.

Availability

DS21352G is available at Aetrix Electronics and suitable for telecom access equipment, ISDN PRI gateways, and T1 network monitoring systems requiring stable component supply, extended temperature operation (-40°C to +85°C), and long-term lifecycle assurance.

Supply support for DS21352G 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 semiconductor company specializing in precision analog, mixed-signal, and high-reliability ICs for communications, industrial, and automotive markets.

The DS21352G belongs to Maxim's SCT (Single-Chip Transceiver) product line, designed specifically for carrier-class T1/E1 line interface applications requiring integrated framer, LIU, jitter control, and robust signaling processing in a single CMOS device.

FAQ

What is the operating voltage range for DS21352G?

The DS21352G operates exclusively at 3.3V ±5% (DVDD, RVDD, TVDD). It is not 5V-tolerant, and applying 5V to any supply or I/O pin will damage the device. This distinguishes it from the pin-compatible DS21552G, which uses a 5V supply. System designs must ensure clean, regulated 3.3V distribution with adequate decoupling per the DS21352G layout guidelines.

Does DS21352G support both D4 and ESF framing formats?

Yes, DS21352G fully supports both D4 (Superframe) and ESF (Extended Superframe) framing structures. Its framer automatically detects and locks to either format, locates multiframe boundaries, extracts/inserts robbed-bit signaling, and monitors associated alarms (e.g., RLOS, RAIS). Configuration is register-controlled and does not require hardware changes - enabling field-upgradable framing mode selection.

How does the elastic store in DS21352G handle clock domain crossing?

The DS21352G implements two independent elastic stores - one on transmit, one on receive - each capable of synchronizing to asynchronous backplane clocks up to 8.192 MHz. They absorb phase and frequency differences between recovered T1 clock (RCLK) and backplane clock (RSYSCLK/TSYSCLK), eliminating metastability risk and enabling seamless interface to packet-switched or ATM backplanes without external FIFOs.

Can DS21352G generate and detect custom in-band loop codes?

Yes, DS21352G supports programmable in-band loop code generation and detection for lengths of 1 to 8 bits, including AT&T-defined CSU loop codes. This is implemented via dedicated registers (LCCR, LCR) and operates per-channel. The feature enables automated remote loopback testing and fault isolation without requiring external loopback plugs or manual line intervention.

Is DS21352G pin-compatible with earlier Maxim T1 transceivers?

Yes, DS21352G is pin-compatible with DS2152, DS2154, DS21354, and DS21554 single-chip transceivers. This allows drop-in replacement in existing designs, preserving PCB layout and mechanical fit. Firmware migration is also simplified, as register maps and control sequences are backward-compatible - though new features (e.g., interleaving PCM bus, JTAG) require updated initialization code.