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Analog Devices Inc./Maxim Integrated DS21348T
- Part No.:
- DS21348T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Telecom
- Package:
- 44-TQFP
- Datasheet:
-
DS21348T.pdf
- Description:
- IC TELECOM INTERFACE 44TQFP
- Quantity:
- Payment:
- Shipping:
Inventory:3,631
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Product details
Overview
DS21348T from Maxim Integrated is a single-channel, 3.3V E1/T1/J1 line interface unit (LIU) supporting both short-haul and long-haul trunks. It delivers full G.703-compliant waveshaping, software-selectable 75Ω/100Ω/120Ω receive termination, crystal-less jitter attenuation (32- or 128-bit FIFO), and AMI/HDB3/B8ZS encoding/decoding - deployed in telecom access equipment for E1/T1 line card designs.
For engineers reviewing the DS21348T datasheet, DS21348T pinout, DS21348T application, or DS21348T equivalent, key selection criteria include hardware-mode configurability, 44-pin TQFP packaging, 0°C to +70°C industrial temperature range, and support for Intel/Motorola parallel, serial, or hardware-only control interfaces without external clock synthesis.
Technical Context
The DS21348T integrates analog front-end circuitry with digital signal processing to recover clock/data from bipolar E1 (AMI/HDB3) or T1 (AMI/B8ZS) waveforms, featuring adaptive receive sensitivity (0dB to –43dB for E1, 0dB to –36dB for T1) and programmable line build-out (–22.5dB to 0dB). Its jitter attenuator operates with only a 2.048MHz master clock (or 1.544MHz for T1), synthesizing backplane clocks at 2.048/4.096/8.192/16.384MHz referenced to RCLK.
Control is implemented via three modes: 8-bit parallel (muxed/nonmuxed, Intel/Motorola timing), 3-wire serial, or dedicated hardware pins - enabling configuration without host processor intervention. The device supports in-band loop codes (1–16 bits), PRBS generation/detection, remote/local/analog loopbacks, and carrier loss detection per ITU-T G.775.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 3.3V ±5% - Enables direct integration into modern 3.3V telecom power domains without level-shifting. |
| Data Rates | E1: 2.048Mbps; T1: 1.544Mbps - Fully compliant with ANSI T1.403-1999, ITU-T G.703/G.704, and ETSI ETS 300 166 standards. |
| Jitter Attenuation | 32-bit or 128-bit FIFO depth - Configurable placement in transmit or receive path to suppress incoming jitter per G.823. |
| Receive Sensitivity | E1: 0dB to –43dB; T1: 0dB to –36dB - Supports operation over 2.5km E1 (22AWG) and 6k ft T1 cables without repeaters. |
| Line Build-Out | E1: 75Ω/120Ω; T1: DSX-1/CSU (0dB, –7.5dB, –15dB, –22.5dB) - Matches physical layer impedance and loss profiles for certified interop. |
| Encoding Support | AMI, HDB3 (E1), B8ZS (T1) - Ensures bit-error-free recovery and transmission across legacy and modern digital trunk networks. |
| Operating Temp | 0°C to +70°C - Qualified for commercial-grade line card deployment in controlled telecom environments. |
Pinout & Package
DS21348T is housed in a 44-pin Thin Quad Flat Package (TQFP), 10mm × 10mm, 0.8mm pitch, RoHS-compliant. Pin functions vary by interface mode (parallel, serial, or hardware); hardware mode uses dedicated control pins (e.g., ETS, L0–L2, DJA) for standalone configuration without microcontroller.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| RTIP / RRING | Analog Receive Inputs | Differential transformer-coupled inputs for E1/T1 waveform recovery; support internal 75Ω/100Ω/120Ω termination selection. |
| TTIP / TRING | Analog Transmit Outputs | High-current line drivers delivering G.703-compliant E1 or DSX-1/CSU-compliant T1 waveshapes to step-up transformer. |
| RCLK | Recovered Clock Output | Buffered, low-jitter clock synchronized to incoming line rate; used as reference for downstream timing or backplane sync. |
| MCLK | Master Clock Input | 2.048MHz (E1/T1) or 1.544MHz (T1-only) TTL-level input driving PLL, jitter attenuator, and clock synthesis blocks. |
| BPCLK | Backplane Clock Output | Synthesized output at 2.048/4.096/8.192/16.384MHz, phase-locked to RCLK - eliminates need for separate clock generators on line cards. |
| RCL/LOTC | Alarm Output | Open-drain output asserting high on receive carrier loss (G.775) or loss of transmit clock - directly drives LED or interrupt logic. |
| HRST | Hardware Reset Input | Active-low asynchronous reset initializing all registers to default state; enables cold-start recovery without firmware dependency. |
Key Features
| Feature | Design Value |
|---|---|
| Crystal-less Jitter Attenuation | 32- or 128-bit FIFO depth selectable in Tx/Rx path - eliminates external VCXO and reduces BOM cost while meeting G.823 jitter specs. |
| Software-Selectable Termination | 75Ω/100Ω/120Ω internal Rx termination - avoids discrete resistor networks and simplifies PCB layout for multi-standard deployments. |
| Hardware Mode Configuration | Dedicated pins (ETS, L0–L2, DJA, JAMUX) enable full LIU setup without host CPU - ideal for boot-time line initialization or fail-safe operation. |
| Multi-Standard Encoding | AMI/HDB3 for E1; AMI/B8ZS for T1 - ensures interoperability with global carrier infrastructure including CEPT, AT&T, and NTT networks. |
| Diagnostic Loopbacks | Remote, local, analog, and dual loopback modes - enables end-to-end link validation and field troubleshooting without external test gear. |
| PRBS Detection & Error Reporting | 2^15–1 or 2^20–1 pattern detection with PBEO pulse output and register-based error counters - provides real-time BER monitoring in production systems. |
Applications
| DSLAM Line Cards | Enterprise TDM Gateways |
|---|---|
Use Scenario: Aggregating multiple E1/T1 lines from copper loops into IP backhaul in DSLAM chassis. IC Role / Device Role / Timing Role: Line interface unit performing clock recovery, jitter cleanup, and G.703-compliant analog drive/receive. Use Value: Enables stable 2.048/1.544MHz timing extraction from noisy copper plant, supporting >2.5km E1 reach and carrier-grade SLA compliance. |
Use Scenario: Bridging legacy TDM voice traffic (PRI/BRI) to VoIP networks in enterprise edge routers. IC Role / Device Role / Timing Role: Physical-layer transceiver converting bipolar T1/E1 signals to NRZ data streams for DSP/FPGA processing. Use Value: Hardware-mode configuration allows rapid line provisioning; integrated PRBS and loopbacks reduce integration test time by >40%. |
| Wireless Backhaul Radios | Industrial SCADA Multiplexers |
Use Scenario: Providing E1 connectivity between microwave base stations and core aggregation nodes. IC Role / Device Role / Timing Role: Jitter-attenuated line interface ensuring low BER under RF interference and temperature cycling. Use Value: 32-bit jitter FIFO maintains <1 UI p-p jitter at RCLK output, preserving synchronization integrity across wireless hop delays. |
Use Scenario: Remote telemetry multiplexing over leased T1 lines in oil/gas pipeline monitoring systems. IC Role / Device Role / Timing Role: Robust T1 LIU with CSU line build-out and AIS alarm detection for unattended field sites. Use Value: Detects and reports blue alarms (AIS) and carrier loss per G.775, triggering automated failover to backup communication paths. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar line interface unit applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| DS2155 | Single-channel, 3.3V, but lacks hardware mode and has fixed 75Ω Rx termination; no 128-bit jitter FIFO. | Targeted at cost-sensitive E1-only designs where software control is mandatory and jitter requirements are less stringent. | Choose DS2155 only if hardware-mode operation and variable termination are unnecessary and BOM cost is primary constraint. |
| MC34115 | 5V operation, older architecture; supports only T1 with B8ZS, no E1/HDB3; requires external oscillator for jitter control. | Legacy T1-only systems with existing 5V power rails and no migration path to 3.3V or multi-standard support. | Select MC34115 only for brownfield T1 replacements where voltage compatibility and pinout reuse outweigh performance limitations. |
Compared with DS2155 and MC34115, the DS21348T uniquely combines E1/T1/J1 dual-standard support, hardware-mode autonomy, crystal-less jitter attenuation, and software-selectable termination - making it the only option for new multi-standard line card designs requiring field-upgradable configuration and G.823 compliance.
Availability
DS21348T is available at Aetrix Electronics and suitable for DSLAM line cards, enterprise TDM gateways, wireless backhaul radios, and industrial SCADA multiplexers requiring stable component supply across extended product lifecycles.
Supply support for DS21348T 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 computing markets.
The DS21348T belongs to Maxim's telecom line interface portfolio, engineered specifically for carrier-class E1/T1 physical layer interfacing in space-constrained, thermally demanding line card applications.
FAQ
What is the operating temperature range for the DS21348T?
The DS21348T is rated for 0°C to +70°C ambient operation. This commercial temperature grade targets indoor telecom equipment such as central office line cards, enterprise gateways, and wireless baseband units where environmental control is maintained. It is distinct from the –40°C to +85°C DS21348TN variant, and thermal derating is not required within this specified range.
Does the DS21348T support both E1 and T1 standards simultaneously?
No - the DS21348T supports either E1 or T1 operation per configuration, selected via the ETS (E1/T1 Select) pin in hardware mode or CCR1.7 in register mode. When ETS = 0, the device configures for E1 (HDB3, 2.048MHz, 75Ω/120Ω); when ETS = 1, it configures for T1 (B8ZS, 1.544MHz, DSX-1/CSU line build-outs). J1 is functionally identical to T1 per datasheet notation.
Can the DS21348T operate without a microcontroller?
Yes - the DS21348T supports hardware mode (BIS1 = BIS0 = 1), using dedicated pins (ETS, L0–L2, DJA, JAMUX, etc.) to configure line standard, termination, loopback, and monitor settings without software. This enables standalone operation in boot-critical or safety-redundant systems where host processor availability cannot be guaranteed.
What clock frequencies does the DS21348T generate on BPCLK?
The DS21348T synthesizes BPCLK at 2.048MHz, 4.096MHz, 8.192MHz, or 16.384MHz - all phase-locked to the recovered RCLK. Selection is controlled by bits CCR5.7 and CCR5.6. In hardware mode, BPCLK defaults to 16.384MHz. These outputs serve as clean, jitter-attenuated system clocks for backplane synchronization or FPGA interface timing.
How does the DS21348T handle receive carrier loss detection?
The DS21348T implements ITU-T G.775-compliant receive carrier loss (RCL) detection. When enabled (CCR2.7 = 0), the RCL/LOTC pin asserts high if no valid signal is detected at RTIP/RRING for >125ms. The same pin doubles as Loss of Transmit Clock (LOTC) when CCR2.7 = 1, toggling high if TCLK remains static for >5µs - providing dual-alarm functionality on a single output.
DS21348T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 44-TQFP
- Packaging:
- Tray
- Product Status:
- Obsolete
- Function:
- Line Interface Unit (LIU)
- Interface:
- -
- Number of Circuits:
- 1
- Voltage - Supply:
- 3.135V ~ 3.465V
- Current - Supply:
- 66mA
- Power (Watts):
- -
- Operating Temperature:
- 0°C ~ 70°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 44-TQFP (10x10)
DS21348T FAQ
1.How can I place an order for DS21348T through Aetrix?
Please submit a Request for Quotation (RFQ) for DS21348T on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for DS21348T reliable?
The price and inventory of DS21348T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for DS21348T is usually 5 days.
3.What payment methods are accepted for DS21348T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for DS21348T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for DS21348T?
DS21348T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your DS21348T order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for DS21348T?
For technical support, including DS21348T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your DS21348T requirements.
6.How does Aetrix verify that DS21348T is sourced from the original manufacturer or authorized distributors?
All DS21348T products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that DS21348T meets industry standards.
7.What is the process for return or replacement of DS21348T?
All DS21348T units undergo pre-shipment inspection (PSI). If there is an issue with DS21348T, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The DS21348T part is unused and in its original packaging.
Return procedure for DS21348T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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