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Analog Devices Inc./Maxim Integrated DS21455+
- Part No.:
- DS21455+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Telecom
- Package:
- 256-BGA
- Datasheet:
-
DS21455+.pdf
- Description:
- IC TELECOM INTERFACE 256BGA
- Quantity:
- Payment:
- Shipping:
Inventory:4,013
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Product details
Overview
DS21455+ from Maxim Integrated is a quad T1/E1/J1 transceiver IC with four independent software-configurable channels, 3.3V supply with 5V-tolerant I/O, 256-ball BGA (27mm × 27mm), and IEEE 1149.1 JTAG boundary scan. It integrates line interface units, framers, dual HDLC controllers, and TDM backplane interface for telecom infrastructure.
For engineers reviewing the DS21455+ datasheet, DS21455+ pinout, DS21455+ application, or DS21455+ equivalent, key selection criteria include per-channel T1/E1/J1 mode flexibility, crystal-less jitter attenuation, programmable termination (75Ω/100Ω/120Ω), dual elastic-store slip buffers, and SS7 signaling support in carrier-grade access equipment.
Technical Context
The DS21455+ implements four fully independent transceiver channels, each with dedicated LIU, framer, and HDLC controller - enabling simultaneous T1, E1, and J1 operation across channels. Each channel supports short- and long-haul line interface with CMI coding/decoding and G.703-compliant transmit/receive waveforms.
Its TDM backplane interface operates up to 16.384MHz with interleaved PCM bus support and dual two-frame elastic-store buffers, while the clock synthesizer delivers 16.384MHz/8.192MHz/4.096MHz/2.048MHz outputs locked to recovered network clock - critical for synchronization-sensitive CSU/DSU and mux applications.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Transceiver Count | Four independent, software-configurable T1/E1/J1 channels - enables multi-standard aggregation on single die. |
| Supply Voltage | 3.3V core with 5V-tolerant I/O - simplifies interface to legacy 5V control logic without level shifters. |
| Package | 256-ball BGA, 27mm × 27mm - standard footprint compatible with DS21Q55 replacement requirements. |
| Jitter Attenuation | Crystal-less jitter attenuator - eliminates external crystal oscillator, reduces BOM count and board space. |
| Termination | Software-selectable 75Ω/100Ω/120Ω receive/transmit termination - supports T1 (100Ω), E1 (120Ω), and J1 (75Ω) physical layer standards. |
| HDLC Controllers | Dual HDLC controllers per channel - enables concurrent data link layer handling for signaling and payload traffic. |
| Clock Synthesis | 16.384MHz/8.192MHz/4.096MHz/2.048MHz outputs synthesized from recovered network clock - ensures phase-coherent timing for TDM switching. |
Pinout & Package
DS21455+ uses a 256-ball fine-pitch BGA package (27mm × 27mm, 1.0mm ball pitch), RoHS-compliant and lead-free. Pin functions are defined per Maxim's DS21455/DS21458 datasheet Rev 051507, Figure 5-1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| TIP0–TIP3, RING0–RING3 | Line interface differential pairs | Four independent T1/E1/J1 analog line connections - each pair supports short/long-haul transmission with programmable termination. |
| TDATA0–TDATA3, RDATA0–RDATA3 | TDM backplane data lanes | Per-channel 8-bit parallel PCM data paths - support interleaved or frame-interleaved bus operation up to 16.384MHz. |
| CLKIN, CLKOUT | System clock reference | Accepts external 2.048MHz/4.096MHz/8.192MHz/16.384MHz reference or drives synthesized clock to backplane. |
| CS, RD, WR, A0–A7 | 8-bit parallel control port | Intel/Motorola-bus configurable interface - enables direct microcontroller connection without glue logic. |
| TMS, TCK, TDI, TDO | JTAG test access port | Single shared JTAG controller for all four transceivers - reduces debug pin count vs. per-channel architecture (e.g., DS21Q55). |
Key Features
| Feature | Design Value |
|---|---|
| Per-channel T1/E1/J1 software configuration | Enables mixed-standard line cards - one DS21455+ can serve North American T1, European E1, and Japanese J1 links simultaneously. |
| Crystal-less jitter attenuator | Eliminates external crystal and associated load capacitors - reduces component count and improves reliability in temperature-varying environments. |
| Dual elastic-store slip buffers per channel | Supports asynchronous backplane interfacing up to 16.384MHz - absorbs clock domain mismatches between line and system clocks without data loss. |
| On-chip BERT generator/detector | Enables in-system bit error rate testing without external test equipment - accelerates production validation and field diagnostics. |
| SS7 and RAI-CI/AIS-CI support | Meets carrier-grade signaling requirements for trunk-side interfaces - required for SS7-based call control and alarm reporting in central office equipment. |
Applications
| Routers | Channel Service Units (CSUs) |
|---|---|
Use Scenario: Multi-service edge routers aggregating T1/E1 leased lines into IP backbone. IC Role / Device Role / Timing Role: Quad transceiver providing physical layer framing, line interface, and TDM-to-backplane conversion for four independent WAN ports. Use Value: Single-chip integration reduces PCB area by >40% vs. discrete transceiver solutions while maintaining per-port configurability and SS7 signaling compliance. | Use Scenario: Carrier-class CSUs performing line conditioning, framing, and alarm monitoring for T1/E1 circuits. IC Role / Device Role / Timing Role: Line interface unit + framer + HDLC controller delivering G.703/G.704/G.732 compliance with real-time AIS/RAI detection. Use Value: Programmable termination and crystal-less jitter attenuation enable drop-in replacement in legacy CSU designs without layout changes. |
| Data Service Units (DSUs) | T1/E1 Test Equipment |
Use Scenario: DSUs converting T1/E1 signals to V.35 or RS-530 for legacy data networks. IC Role / Device Role / Timing Role: Physical layer transceiver with dual HDLC controllers handling both signaling and data encapsulation for protocol bridging. Use Value: Dual HDLC engines allow simultaneous D-channel (signaling) and B-channel (payload) processing - eliminating need for external HDLC chips. | Use Scenario: Portable T1/E1 analyzers performing line diagnostics, BER testing, and alarm injection. IC Role / Device Role / Timing Role: Integrated BERT generator/detector, loopback modes, and programmable error insertion for self-contained test functionality. Use Value: On-chip BERT and elastic-store buffers enable full physical-layer testing without external pattern generators or sync sources - reducing instrument size and cost. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar quad T1/E1 transceiver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| DS21455N+ | Extended temperature range (−40°C to +85°C) vs. DS21455+ (0°C to +70°C); identical pinout, register map, and functionality. | Suitable for industrial outdoor cabinets or base station environments requiring wider thermal tolerance. | Select DS21455N+ when operating ambient exceeds 70°C or falls below 0°C; otherwise DS21455+ suffices for commercial indoor telecom gear. |
| DS21458+ | Smaller 17mm CSBGA package, improved controller interface timing, same software compatibility; JTAG remains single-controller architecture. | Better suited for space-constrained line cards where 27mm BGA is prohibitive; no change in functional capability. | Choose DS21458+ when board area is constrained and 17mm footprint is acceptable; DS21455+ preferred for drop-in DS21Q55 replacement. |
Compared with DS21455N+ and DS21458+, the DS21455+ offers optimal balance of commercial-temperature operation, proven 27mm BGA compatibility with legacy DS21Q55 layouts, and full feature parity - making it the default choice for new indoor CSU/DSU designs not requiring extended temp or miniaturization.
Availability
DS21455+ is available at Aetrix Electronics and suitable for routers, channel service units (CSUs), data service units (DSUs), multiplexers, and telecom test equipment requiring stable component supply, RoHS compliance, and long-term lifecycle support.
Supply support for DS21455+ 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 RF ICs for communications, computing, and industrial markets.
The DS21455+ belongs to Maxim's telecom transceiver product line, designed specifically for carrier-access and enterprise-edge equipment requiring multi-standard T1/E1/J1 physical layer integration with minimal external components.
FAQ
What is the operating temperature range for DS21455+?
The DS21455+ is rated for commercial temperature operation from 0°C to +70°C. This range is validated per Maxim's ordering information table and applies to all electrical and timing specifications in the DS21455/DS21458 datasheet Rev 051507. For extended temperature applications, the DS21455N+ variant (−40°C to +85°C) is available with identical functionality and pinout.
Is DS21455+ pin-compatible with DS21Q55?
Yes, DS21455+ is a direct replacement for DS21Q55 per Maxim's General Description and Ordering Information sections. It maintains identical 256-ball BGA (27mm × 27mm) mechanical footprint, pin assignments, and register-level software compatibility - enabling drop-in upgrade without PCB redesign.
Does DS21455+ support both T1 and E1 framing simultaneously across its four channels?
Yes, DS21455+ supports independent software configuration per channel: any combination of T1, E1, or J1 operation is possible. Each channel's framer, LIU, and HDLC controller operate autonomously, allowing mixed-standard line cards - e.g., two T1 and two E1 ports on a single DS21455+.
What clock frequencies does DS21455+ synthesize for backplane use?
DS21455+ synthesizes 16.384MHz, 8.192MHz, 4.096MHz, or 2.048MHz clock outputs, all phase-locked to the recovered network clock. These frequencies align with T1 (1.544MHz × 10.625 = 16.384MHz) and E1 (2.048MHz × 1/2/4/8) timing hierarchies, enabling synchronous TDM switching without external PLLs.
How does the JTAG architecture differ between DS21455+ and DS21Q55?
DS21455+ uses a single JTAG controller shared across all four transceivers, whereas DS21Q55 implemented separate JTAG controllers per channel. This reduces JTAG pin count and simplifies boundary-scan test setup, though per-channel debug visibility requires sequential channel selection via software rather than parallel access.
DS21455+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 256-BGA
- Packaging:
- Tray
- Product Status:
- Obsolete
- Function:
- Line Interface Unit (LIU)
- Interface:
- LIU
- Number of Circuits:
- 4
- Voltage - Supply:
- 3.135V ~ 3.465V
- Current - Supply:
- -
- Power (Watts):
- -
- Operating Temperature:
- 0°C ~ 70°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 256-BGA (27x27)
DS21455+ FAQ
1.How can I place an order for DS21455+ through Aetrix?
Please submit a Request for Quotation (RFQ) for DS21455+ 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 DS21455+ reliable?
The price and inventory of DS21455+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for DS21455+ is usually 5 days.
3.What payment methods are accepted for DS21455+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for DS21455+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for DS21455+?
DS21455+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your DS21455+ 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 DS21455+?
For technical support, including DS21455+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your DS21455+ requirements.
6.How does Aetrix verify that DS21455+ is sourced from the original manufacturer or authorized distributors?
All DS21455+ 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 DS21455+ meets industry standards.
7.What is the process for return or replacement of DS21455+?
All DS21455+ units undergo pre-shipment inspection (PSI). If there is an issue with DS21455+, 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 DS21455+ part is unused and in its original packaging.
Return procedure for DS21455+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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