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Analog Devices Inc./Maxim Integrated DS21348TN
- Part No.:
- DS21348TN
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Telecom
- Package:
- 44-TQFP
- Datasheet:
-
DS21348TN.pdf
- Description:
- IC TELECOM INTERFACE 44TQFP
- Quantity:
- Payment:
- Shipping:
Inventory:3,656
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Product details
Overview
DS21348TN from Maxim Integrated is a single-channel, 3.3V E1/T1/J1 line interface unit (LIU) supporting long-haul and short-haul trunks with software-selectable 75Ω/100Ω/120Ω receive termination, crystal-less jitter attenuation (32-bit or 128-bit FIFO), and full G.703/G.704/ANSI T1.403 compliance. It operates across –40°C to +85°C in 44-pin TQFP and drives E1 (0dB to –43dB sensitivity) or T1 (0dB to –36dB) lines via TTIP/TRING.
For engineers reviewing the DS21348TN datasheet, DS21348TN pinout, DS21348TN application, or DS21348TN equivalent, key selection criteria include its dual-standard E1/T1 support, internal line build-out generation (E1: 75Ω/120Ω; T1: DSX-1/CSU), bipolar/NRZ data I/O, programmable monitor mode, and hardware/serial/parallel interface flexibility - all critical for telecom infrastructure design.
Technical Context
The DS21348TN integrates clock/data recovery, AMI/HDB3/B8ZS encoding/decoding, and configurable analog front-end filtering. Its jitter attenuator is placed in either transmit or receive path and synthesizes backplane clocks (2.048MHz–16.384MHz) locked to RCLK, using only a 2.048MHz (or optional 1.544MHz) MCLK.
It supports three control modes: 8-bit parallel (muxed/non-muxed, Intel/Motorola timing), serial (SPI-like), or hardware mode with dedicated pins for loopback, PRBS, and line build-out selection. Receive sensitivity is programmable (E1: 0dB to –43dB; T1: 0dB to –36dB), and transmit open-circuit detection, RCL (G.775), and AIS alarm generation are embedded.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 3.3V ±5% - Enables direct integration into modern low-voltage telecom systems without level-shifting. |
| Data Standards | E1 (ITU G.703/G.704), T1 (ANSI T1.403-1999), J1 - Single device supports global telephony framing standards. |
| Receive Sensitivity | E1: 0dB to –43dB; T1: 0dB to –36dB - Supports operation over 2.5km E1 (22AWG) and 6k ft T1 cables. |
| Jitter Attenuation | Crystal-less, 32-bit or 128-bit FIFO depth - Eliminates external crystal requirement while maintaining E1/T1 jitter tolerance compliance. |
| Line Build-Out | E1: 75Ω/120Ω waveshaping; T1: DSX-1 (0/–7.5/–15/–22.5dB) and CSU options - Configurable analog output drive for diverse trunk types. |
| Interface Modes | 8-bit parallel (Intel/Motorola), serial (3-wire), or hardware mode - Enables flexible host controller integration without protocol translation. |
| Encoding Support | AMI, HDB3 (E1), B8ZS (T1) - Full physical-layer coding compliance for error-free line signaling. |
Pinout & Package
DS21348TN is housed in a 44-pin Thin Quad Flat Package (TQFP), 10mm × 10mm, 0.8mm pitch, RoHS-compliant (lead-free). Pin functions vary by interface mode (parallel, serial, or hardware); all configurations share common analog I/O (RTIP/RRING, TTIP/TRING), clock (MCLK, RCLK, TCLK, BPCLK), and control (HRST, INT, TEST) terminals.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| RTIP / RRING | Analog receive inputs | Transformer-coupled differential inputs for E1/T1 waveform recovery; support internal 75Ω/100Ω/120Ω termination selection. |
| TTIP / TRING | Analog transmit outputs | Differential line driver outputs with programmable line build-out; high-impedance state enabled during fault conditions. |
| RPOS / RNEG | Bipolar/NRZ receive data | Recovered data outputs synchronized to RCLK; NRZ mode uses RPOS for data and RNEG for error pulses. |
| TPOS / TNEG | Bipolar/NRZ transmit data | Input data sampled on TCLK edge; NRZE bit (CCR1.6) selects NRZ vs. bipolar transmission format. |
| MCLK | Master clock input | 2.048MHz (±50ppm) TTL-level reference for clock recovery and jitter attenuation; 1.544MHz optional for T1-only use. |
| RCLK | Recovered clock output | Buffered line-recovered clock, synchronous to MCLK when no signal present; used as timing reference for backplane clock synthesis. |
| BPCLK | Backplane clock output | Synthesized 2.048/4.096/8.192/16.384MHz clock derived from RCLK - provides system-synchronized timing for downstream logic. |
| HRST | Hardware reset input | Active-low asynchronous reset that clears all registers to default (0x00); required for deterministic power-up initialization. |
Key Features
| Feature | Design Value |
|---|---|
| Crystal-less jitter attenuation | 32-bit or 128-bit FIFO eliminates need for external crystal oscillator while meeting ITU G.823 jitter tolerance specs. |
| Programmable receive termination | Software-selectable 75Ω/100Ω/120Ω internal termination reduces BOM count and enables field reconfiguration for different line impedances. |
| Multi-standard line build-out | On-chip generation of E1 CEPT 30/ISDN-PRI waveshapes and T1 DSX-1/CSU line build-outs avoids discrete filter networks. |
| Integrated diagnostics | PRBS generation/detection (2^15–1, 2^20–1), in-band loop code (1–16 bits), and local/remote/analog loopbacks enable full line validation without external test gear. |
| Triple-interface control | Parallel (Intel/Motorola), serial (3-wire), or hardware-mode configuration allows optimal host MCU interface choice without firmware overhead. |
Applications
| Channel Bank Interface | DSLAM Line Card |
|---|---|
|
Use Scenario: Aggregating multiple E1/T1 feeds into a centralized switching fabric within carrier-class channel banks. IC Role / Device Role / Timing Role: Line interface unit providing physical-layer E1/T1 termination, clock recovery, and jitter cleanup before framing and multiplexing. Use Value: Enables single-chip per-line termination with programmable line build-out and crystal-less jitter attenuation, reducing board space and component count. |
Use Scenario: Providing legacy T1/E1 uplink ports on DSL access multiplexers serving business customers. IC Role / Device Role / Timing Role: Physical layer transceiver handling AMI/B8ZS/HDB3 coding, receive sensitivity adaptation, and AIS alarm generation. Use Value: Supports both short-haul (DSX-1) and long-haul (CSU) T1 deployments with identical hardware, simplifying inventory and qualification. |
| Network Access Server | Enterprise PBX Gateway |
|
Use Scenario: Connecting enterprise WAN links to service provider networks via E1 or T1 handoff points. IC Role / Device Role / Timing Role: Bidirectional LIU managing line synchronization, carrier loss detection (G.775), and loopback testing for remote diagnostics. Use Value: Integrated RCL, PRBS, and in-band loop code support enables automated provisioning and SLA verification without manual intervention. |
Use Scenario: Integrating PRI (E1/T1) trunks into IP-PBX systems requiring ISDN signaling compatibility. IC Role / Device Role / Timing Role: Physical layer interface converting bipolar line signals to NRZ data streams for upstream protocol processing. Use Value: NRZ mode (via NRZE bit) and 8-bit parallel interface allow direct connection to ARM/FPGA-based PBX controllers without glue logic. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar line interface unit applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| DS2155N | Single-channel, 3.3V, but lacks crystal-less jitter attenuator and supports only T1 (no E1). | Targeted at cost-sensitive T1-only applications where jitter attenuation is handled externally. | Choose DS2155N only if E1 support and integrated jitter cleanup are unnecessary. |
| MAX3089CSD+ | RS-485 transceiver, not an LIU - no clock recovery, encoding/decoding, or line build-out capability. | Designed for multi-drop data communication, not telecom line interfacing. | Not functionally equivalent; unsuitable as a replacement for DS21348TN in E1/T1 line card designs. |
Compared with DS21348TN, DS2155N offers lower system cost in pure T1 environments but sacrifices E1 compatibility and jitter attenuation integration; MAX3089CSD+ serves entirely different physical layer requirements and cannot fulfill DS21348TN's line interface role.
Availability
DS21348TN is available at Aetrix Electronics and suitable for telecom infrastructure, network access equipment, and carrier-grade channel bank designs requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for DS21348TN 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 power management ICs for industrial, communications, and computing markets.
The DS21348TN belongs to Maxim's telecom line interface product line, engineered specifically for carrier-class E1/T1/J1 physical layer termination with integrated clock recovery, jitter attenuation, and diagnostic features.
FAQ
What is the operating temperature range for the DS21348TN?
The DS21348TN is rated for industrial operation from –40°C to +85°C. This extended range ensures reliable performance in uncontrolled telecom cabinet environments, including outdoor DSLAMs and central office line cards where ambient temperatures fluctuate significantly. The DS21348TN's thermal characteristics are validated per JEDEC JESD51-2, with θJA = 42°C/W in standard 4-layer PCB layout.
Does the DS21348TN support both E1 and T1 standards simultaneously?
Yes, the DS21348TN supports both E1 and T1 standards in a single device, selected via the ETS bit (CCR1.7). When ETS = 0, it configures for E1 (G.703 75Ω/120Ω, HDB3); when ETS = 1, it configures for T1 (DSX-1/CSU, B8ZS). The DS21348TN does not operate in dual-standard mode concurrently - configuration is static per power-on or register write.
What master clock frequencies does the DS21348TN accept?
The DS21348TN accepts a 2.048MHz ±50ppm TTL-level MCLK for both E1 and T1 operation. For T1-only applications, a 1.544MHz MCLK is optionally supported. The DS21348TN does not accept arbitrary frequencies - MCLK must match one of these two specified rates to ensure proper clock/data recovery and jitter attenuator operation.
How is receive termination configured on the DS21348TN?
Receive termination on the DS21348TN is software-selectable via Internal Rx Termination Select bits (CCR5.1:CCR5.0) to 75Ω, 100Ω, or 120Ω. This setting applies to the internal termination between RTIP and RRING and eliminates the need for external resistors. The DS21348TN also supports external termination configurations, where internal termination is disabled and external network components define impedance.
Can the DS21348TN generate backplane clocks synchronized to the recovered line clock?
Yes, the DS21348TN synthesizes BPCLK (backplane clock) at 2.048MHz, 4.096MHz, 8.192MHz, or 16.384MHz, all phase-locked to RCLK. This is controlled by CCR5.7 and CCR5.6. The DS21348TN's BPCLK output provides a jitter-clean, system-synchronized timing reference for FPGA, ASIC, or DSP subsystems - eliminating need for separate clock generators in line card designs.
DS21348TN 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:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 44-TQFP (10x10)
DS21348TN FAQ
1.How can I place an order for DS21348TN through Aetrix?
Please submit a Request for Quotation (RFQ) for DS21348TN 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 DS21348TN reliable?
The price and inventory of DS21348TN are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for DS21348TN is usually 5 days.
3.What payment methods are accepted for DS21348TN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for DS21348TN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for DS21348TN?
DS21348TN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your DS21348TN 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 DS21348TN?
For technical support, including DS21348TN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your DS21348TN requirements.
6.How does Aetrix verify that DS21348TN is sourced from the original manufacturer or authorized distributors?
All DS21348TN 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 DS21348TN meets industry standards.
7.What is the process for return or replacement of DS21348TN?
All DS21348TN units undergo pre-shipment inspection (PSI). If there is an issue with DS21348TN, 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 DS21348TN part is unused and in its original packaging.
Return procedure for DS21348TN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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