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Analog Devices Inc./Maxim Integrated DS21448N
- Part No.:
- DS21448N
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Telecom
- Package:
- 144-BGA
- Datasheet:
-
DS21448N.pdf
- Description:
- IC TELECOM INTERFACE 144BGA
- Quantity:
- Payment:
- Shipping:
Inventory:1,136
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Product details
Overview
DS21448N from Maxim Integrated is a quad-port E1/T1/J1 line interface unit (LIU) supporting simultaneous short-haul and long-haul trunk operation across four independent channels. It operates at 3.3V, integrates 32-bit/128-bit crystal-less jitter attenuation, supports G.703 E1 waveshaping (75Ω/120Ω), and delivers DSX-1/CSU line build-outs (0dB to –22.5dB) for T1 in telecom access platforms and wireless base stations.
For engineers reviewing the DS21448N datasheet, DS21448N pinout, DS21448N application, or DS21448N equivalent, key selection considerations include its quad-channel E1/T1/J1 compatibility, software-selectable receive termination (75Ω/100Ω/120Ω), AMI/HDB3/B8ZS encoding/decoding, JTAG boundary scan (IEEE 1149.1), and –40°C to +85°C industrial temperature rating in 144-pin TE-PBGA.
Technical Context
The DS21448N implements four fully independent LIU channels with integrated transmit drivers and receivers, each capable of E1 (2.048MHz) or T1 (1.544MHz) operation. Its jitter attenuator synthesizes 16.384MHz/8.192MHz/4.096MHz/2.048MHz backplane clocks from recovered RCLK without external crystal, using only MCLK input.
Each channel features programmable monitor mode, in-band loop-code generation/detection (1–16 bits), PRBS pattern generation/detection, and dual-mode loopbacks (remote/local/analog). The analog interface supports NRZ/bipolar I/O, transmit open-circuit detection, and receive carrier loss (RCL) per G.775, with high-Z TTIP/TRING control and 50mARMS current limiting.
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. |
| Operating Temperature | –40°C to +85°C - Qualified for industrial-grade deployment in central-office switches and outdoor wireless base stations. |
| Line Interface Standards | ANSI T1.403-1999, ITU G.703/G.704/G.706/G.775, ETSI ETS 300 166 - Ensures interoperability with global E1/T1 infrastructure. |
| Jitter Attenuation | 32-bit or 128-bit crystal-less - Eliminates need for external crystal oscillator while maintaining <1.5UI peak-to-peak jitter on recovered clock. |
| Encoding Support | AMI, HDB3, B8ZS - Provides full protocol compliance for E1 (HDB3), T1 (B8ZS), and legacy AMI systems. |
| Line Build-Out | E1: G.703-compliant waveshape; T1: DSX-1/CSU options at 0dB, –7.5dB, –15dB, –22.5dB - Matches exact cable loss profiles for reliable long-haul transmission. |
| Interface Type | 8-bit parallel (Intel/Motorola muxed/non-muxed) or serial (SPI-like) - Supports flexible host controller integration with minimal pin count overhead. |
Pinout & Package
DS21448N is housed in a 144-ball TE-PBGA (56-G6020-001) package with 0.8mm ball pitch, designed for high-density telecom PCB layouts and thermal management via exposed thermal pad.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| RTIP1–RTIP4 / RRING1–RRING4 | Analog receive inputs | Differential bipolar inputs for clock/data recovery from E1/T1 lines via 1:1 transformer coupling. |
| TTIP1–TTIP4 / TRING1–TRING4 | Analog transmit outputs | Differential line-driver outputs with 50mARMS current limiting and open-circuit detection for robust physical layer signaling. |
| RPOS1–RPOS4 / RNEG1–RNEG4 | Recovered data outputs | NRZ or bipolar data outputs synchronized to RCLK; RNEG pulses indicate BPV/CV/EXZ errors. |
| RCLK1–RCLK4 | Recovered clock output | Buffered line-recovered clock, synchronous to MCLK when no signal present - used for timing downstream logic. |
| BPCLK1–BPCLK4 | Synthesized backplane clock | Programmable 16.384/8.192/4.096/2.048MHz output derived from RCLK - eliminates need for multiple clock sources on board. |
| CS1–CS4 | Channel select inputs | Independent active-low chip selects enabling per-channel register access without bus contention. |
| MCLK | Master clock input | Accepts 2.048MHz (E1) or optional 1.544MHz (T1) TTL-level reference - drives jitter attenuator and clock recovery blocks. |
| JTMS/JTCK/JTDI/JTDO/JTRST | JTAG test port | Full IEEE 1149.1 boundary scan support for production testing and in-system diagnostics. |
Key Features
| Feature | Design Value |
|---|---|
| Quad independent E1/T1/J1 LIUs | Four fully isolated transceivers enable single-chip aggregation of four T1/E1 links - reduces BOM count and board space vs. discrete solutions. |
| Software-selectable receive termination | 75Ω/100Ω/120Ω termination configurable per channel via CCR registers - adapts to diverse line impedances without hardware changes. |
| Crystal-less jitter attenuator | 32-bit or 128-bit PLL-based attenuation using only MCLK - removes crystal cost, footprint, and aging drift while meeting G.823 jitter specs. |
| In-band loop code generation/detection | Generates and detects 1–16-bit in-band codes including CSU-specific patterns - enables standards-compliant remote fault isolation and maintenance. |
| PRBS generation and error detection | On-chip QRSS (T1) or 215–1 (E1) pattern generator with bit-error pulse output (PBEO) and register-based error counters - accelerates link validation and BER testing. |
| JTAG boundary scan | IEEE 1149.1-compliant test access port - supports automated PCB assembly verification and interconnect testing in high-reliability telecom systems. |
Applications
| Integrated Multiservice Access Platforms | T1/E1 Cross-Connects |
|---|---|
Use Scenario: Aggregating mixed E1/T1 traffic from DSLAMs, fiber nodes, and legacy PBXs into a unified IP/MPLS edge router. IC Role / Device Role / Timing Role: DS21448N serves as the physical-layer line interface, performing clock recovery, line coding, and jitter attenuation for all four E1/T1 ports. Use Value: Single-chip quad LIU eliminates four separate transceiver ICs, reducing power by 35% and PCB area by 42% versus dual-channel alternatives. | Use Scenario: Reconfigurable TDM switching fabric in metro aggregation nodes handling leased-line handoffs between carriers. IC Role / Device Role / Timing Role: DS21448N provides bidirectional T1/E1 framing, in-band loopback initiation, and AIS alarm generation for circuit provisioning and SLA monitoring. Use Value: Hardware-mode loopback control and real-time RCL/LOTC reporting enable sub-second fault localization without host CPU intervention. |
| Central-Office Switch Interfaces | Wireless Base Stations |
Use Scenario: Interfacing legacy Class 5 switches with modern VoIP gateways via T1 trunks in CO environments with strict EMI and thermal constraints. IC Role / Device Role / Timing Role: DS21448N acts as the line-facing PHY, delivering G.703-compliant E1 waveforms and detecting blue (AIS) alarms per G.775. Use Value: –40°C to +85°C rating and 75Ω/120Ω termination flexibility ensure stable operation across varying CO cabinet temperatures and cabling types. | Use Scenario: Backhaul connectivity in 4G/LTE macrocells where E1/T1 links carry user-plane and control-plane traffic to RNC/BSC. IC Role / Device Role / Timing Role: DS21448N handles physical-layer synchronization, jitter cleanup, and PRBS-based link integrity checks for fronthaul/backhaul handoff. Use Value: Crystal-less jitter attenuator meets ITU-T G.823 mask requirements even under variable temperature and vibration, avoiding crystal microphonics-induced jitter. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar quad E1/T1 line interface applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| DS21Q348 | Same pinout and register map but lacks JTAG boundary scan and has different jitter attenuator architecture (non-crystal-less). | Targeted at cost-sensitive, non-test-critical designs where IEEE 1149.1 is not required. | Select DS21Q348 only if JTAG test capability is unnecessary and MCLK-derived jitter attenuation is acceptable. |
| MAX3440 | Single-port T1/E1 LIU with integrated transformer driver; no quad integration or crystal-less jitter attenuation. | Used in low-channel-count applications like small office routers or embedded telemetry gateways. | Choose MAX3440 when system requires only one T1/E1 port and board space allows discrete magnetics plus separate jitter cleaner. |
Compared with DS21Q348, DS21448N adds JTAG testability and superior crystal-less jitter performance; compared with MAX3440, it delivers 4× channel density and eliminates need for external jitter attenuators or multiple discrete LIUs - critical for multiservice access platforms requiring compact, testable, and thermally robust designs.
Availability
DS21448N is available at Aetrix Electronics and suitable for integrated multiservice access platforms, T1/E1 cross-connects, and wireless base station backhaul requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for DS21448N 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 high-performance analog, mixed-signal, and RF solutions for communications, computing, and industrial markets.
The DS21448N belongs to Maxim's T1/E1/J1 line interface product line, engineered for carrier-grade telecom infrastructure where reliability, jitter performance, and multi-standard compliance are mandatory.
FAQ
What is the operating temperature range of the DS21448N?
The DS21448N is rated for –40°C to +85°C, making it suitable for industrial and outdoor telecom deployments including central-office switches and wireless base stations. This extended range exceeds the 0°C to +70°C specification of commercial-grade variants like DS21448, ensuring reliability under thermal stress without derating. DS21448N maintains full electrical performance-including jitter attenuation, line build-out accuracy, and PRBS error detection-across this entire range.
Does the DS21448N require an external crystal oscillator?
No, the DS21448N features an integrated 32-bit or 128-bit crystal-less jitter attenuator that synthesizes stable backplane clocks (16.384MHz, 8.192MHz, 4.096MHz, or 2.048MHz) directly from the recovered RCLK or MCLK input. This eliminates the need for an external crystal, reducing bill-of-materials cost, PCB footprint, and potential failure modes related to crystal aging or shock sensitivity. DS21448N achieves G.823-compliant jitter performance without any external timing components.
How does the DS21448N support both E1 and T1 line standards?
The DS21448N supports E1 (2.048Mbps) and T1 (1.544Mbps) through hardware- and register-configurable settings: ETS bit (CCR1.7) selects E1 vs. T1 mode, determining PRBS pattern type (215–1 vs. QRSS), clock synthesis, and line build-out tables. It decodes AMI/HDB3 for E1 and AMI/B8ZS for T1, generates G.703-compliant E1 waveshapes, and applies DSX-1/CSU build-outs for T1. DS21448N meets ANSI T1.403-1999, ITU G.703, and ETSI ETS 300 166 in both modes.
What diagnostic capabilities does the DS21448N provide?
The DS21448N includes comprehensive diagnostics: per-channel PRBS generation/detection with PBEO pulse output and ECR register error counting; in-band loop-code generation/detection (1–16 bits, including CSU); three loopback modes (remote, local, analog); and real-time alarm reporting (AIS, RCL/LOTC, BPV/CV/EXZ). These functions operate independently per channel and can be enabled via hardware pins or register writes - enabling rapid field troubleshooting without host processor involvement. DS214448N also supports JTAG boundary scan per IEEE 1149.1 for production test.
Can the DS21448N interface with both Intel- and Motorola-style parallel buses?
Yes, the DS21448N supports both Intel- and Motorola-style 8-bit parallel interfaces via the PBTS pin: when PBTS = 0, it uses Intel timing (RD/WR/ALE); when PBTS = 1, it uses Motorola timing (DS/RW/AS). Bus multiplexing is controlled by BIS0 (multiplexed if low, non-multiplexed if high), and address/data separation is handled accordingly. This dual-bus compatibility allows seamless integration with legacy and modern microcontrollers, FPGAs, and ASICs without glue logic. DS21448N also supports serial (SPI-like) and hardware-only modes for minimal-pin-count implementations.
DS21448N Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 144-BGA
- Packaging:
- Tray
- Product Status:
- Active
- Function:
- Line Interface Unit (LIU)
- Interface:
- -
- Number of Circuits:
- 4
- Voltage - Supply:
- 3.135V ~ 3.465V
- Current - Supply:
- 320mA
- Power (Watts):
- -
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 144-TEPBGA (17x17)
DS21448N FAQ
1.How can I place an order for DS21448N through Aetrix?
Please submit a Request for Quotation (RFQ) for DS21448N 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 DS21448N reliable?
The price and inventory of DS21448N are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for DS21448N is usually 5 days.
3.What payment methods are accepted for DS21448N?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for DS21448N transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for DS21448N?
DS21448N orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your DS21448N 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 DS21448N?
For technical support, including DS21448N datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your DS21448N requirements.
6.How does Aetrix verify that DS21448N is sourced from the original manufacturer or authorized distributors?
All DS21448N 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 DS21448N meets industry standards.
7.What is the process for return or replacement of DS21448N?
All DS21448N units undergo pre-shipment inspection (PSI). If there is an issue with DS21448N, 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 DS21448N part is unused and in its original packaging.
Return procedure for DS21448N:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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