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Analog Devices Inc./Maxim Integrated DS21348G
- Part No.:
- DS21348G
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Telecom
- Package:
- 49-LFBGA, CSPBGA
- Datasheet:
-
DS21348G.pdf
- Description:
- IC TELECOM INTERFACE 49CSBGA
- Quantity:
- Payment:
- Shipping:
Inventory:2,210
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Product details
Overview
DS21348G 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 programmable receive-side termination (75Ω/100Ω/120Ω), crystal-less jitter attenuation (32-bit or 128-bit FIFO), and full G.703/G.704/G.775 compliance for telecom infrastructure applications including CSU/DSX-1 and CEPT 30/ISDN-PRI line interfaces.
For engineers reviewing the DS21348G datasheet, DS21348G pinout, DS21348G application, or DS21348G equivalent, this device requires attention to MCLK selection (2.048MHz or optional 1.544MHz), hardware/software interface mode configuration (BIS0/BIS1), backplane clock synthesis (BPCLK at 2.048–16.384MHz), and analog interface design for TTIP/TRING and RTIP/RRING transformer coupling.
Technical Context
The DS21348G integrates full E1/T1 physical layer functions: clock/data recovery with adaptive receive sensitivity (0dB to –43dB for E1, 0dB to –36dB for T1), AMI/HDB3/B8ZS encoding/decoding, and programmable line build-out (0dB, –7.5dB, –15dB, –22.5dB). Its jitter attenuator operates in either transmit or receive path and supports 32-bit or 128-bit depth selection via register control.
It features three configurable control interfaces - 8-bit parallel (muxed/nonmuxed Intel/Motorola), serial (SPI-like), or hardware mode - with dedicated pins for loopback control (RLB/LLB/ALB), PRBS generation/detection, and in-band loop code handling (1–16 bits). The device outputs RCLK-synchronized BPCLK and supports NRZ/bipolar data I/O on RPOS/RNEG and TPOS/TNEG.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 3.3V ±5% - fixed single-rail operation; no 5V support per revision history. |
| Data Rates | E1: 2.048Mbps; T1: 1.544Mbps - fully compliant with ANSI T1.403-1999 and ITU G.704. |
| Jitter Attenuation | Crystal-less, 32-bit or 128-bit FIFO depth - eliminates need for external crystal while maintaining G.823 jitter tolerance. |
| Receive Sensitivity | E1: 0dB to –43dB; T1: 0dB to –36dB - enables operation over 2.5km (E1) or 6k ft (T1) on 22AWG cable. |
| Line Build-Out | E1: 75Ω/120Ω waveshaping; T1: DSX-1/CSU options (0dB, –7.5dB, –15dB, –22.5dB) - meets G.703 output mask requirements. |
| Encoding Support | AMI, HDB3 (E1), B8ZS (T1) - selectable per standard via register configuration, not hardware pin. |
| Backplane Clock | 2.048MHz, 4.096MHz, 8.192MHz, or 16.384MHz synthesized from RCLK - provides synchronous system timing without external PLL. |
Pinout & Package
DS21348G uses a 49-ball CSBGA package (7mm × 7mm, RoHS-compliant), rated for 0°C to +70°C operation. Pin assignments are mode-dependent (parallel/serial/hardware); all modes share core analog I/O (RTIP/RRING, TTIP/TRING) and power (VDD/VSS) pins.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| RTIP / RRING | Analog Receive Inputs | Differential transformer-coupled inputs for E1/T1 waveform recovery; support internal software-selectable termination (75Ω/100Ω/120Ω). |
| TTIP / TRING | Analog Transmit Outputs | Differential line driver outputs requiring external step-up transformer; support CSU/DSX-1/E1 waveshaping per register settings. |
| RPOS / RNEG | Recovered Data Outputs | Bipolar or NRZ data synchronized to RCLK; RNEG pulses on error in NRZ mode per CCR1.6 setting. |
| TPOS / TNEG | Transmit Data Inputs | Sampled on TCLK edge (configurable rising/falling); feed into jitter attenuator and waveshaping circuitry before line drive. |
| RCLK | Recovered Clock Output | Buffered line-recovered clock, stable during signal presence; used as reference for BPCLK synthesis and host timing. |
| MCLK | Master Clock Input | 2.048MHz (±50ppm) TTL-level input required for clock recovery and jitter attenuation; 1.544MHz allowed for T1-only use. |
| BIS0 / BIS1 | Bus Interface Select | Two-pin configuration determining control interface: parallel (muxed/nonmuxed), serial, or hardware mode per Table 2-1. |
| HRST | Hardware Reset Input | Active-low asynchronous reset; initializes all registers to default state (all zeros) and disables outputs until deasserted. |
Key Features
| Feature | Design Value |
|---|---|
| Crystal-less Jitter Attenuation | 32-bit or 128-bit FIFO depth selectable in TX or RX path - eliminates external crystal while meeting G.823 jitter transfer specs. |
| Programmable Line Build-Out | Four discrete T1 levels (0dB, –7.5dB, –15dB, –22.5dB) and E1 75Ω/120Ω waveshaping - ensures G.703 compliance across cable lengths and topologies. |
| Multi-Standard Encoding | AMI/HDB3 for E1; AMI/B8ZS for T1 - handled in silicon with register-controlled selection, no external logic needed. |
| Three Control Interface Options | 8-bit parallel (Intel/Motorola, muxed/nonmuxed), serial (SPI-compatible), or hardware mode - enables flexible integration with legacy and modern controllers. |
| Comprehensive Diagnostics | PRBS gen/detect (2^15–1 or 2^20–1), in-band loop codes (1–16 bits), and four loopback types (RLB/LLB/ALB/DLB) - supports field validation and remote maintenance. |
| G.775 Receive Carrier Loss Detection | Dedicated RCL/LOTC pin toggles on loss of valid signal at RTIP/RRING or missing TCLK edges - enables fast fault isolation in carrier-grade systems. |
Applications
| Channel Bank Interface | CSU/DSX-1 Line Card |
|---|---|
|
Use Scenario: Aggregating multiple T1/E1 lines into a digital switch fabric using channelized time-division multiplexing. IC Role / Device Role / Timing Role: Physical layer line interface providing clock recovery, framing alignment, and analog line driving/receiving. Use Value: Enables direct connection to legacy telco infrastructure with full ANSI/ITU compliance and built-in jitter cleanup for backplane synchronization. |
Use Scenario: Deploying modular T1 line cards in central office equipment requiring DSX-1 or CSU line build-out configurations. IC Role / Device Role / Timing Role: Programmable LIU delivering precise line impedance matching and output waveshaping per AT&T TR 62411 and ANSI T1.408. Use Value: Eliminates discrete filter networks and external clock clean-up ICs, reducing BOM count and board area by >30% versus discrete solutions. |
| ISDN-PRI Access Node | Remote Terminal Unit (RTU) |
|
Use Scenario: Providing E1-based ISDN Primary Rate Interface connectivity in enterprise PBX or access concentrators. IC Role / Device Role / Timing Role: CEPT 30-line interface with HDB3 encoding, blue alarm (AIS) detection, and high-impedance TTIP/TRING for transformer isolation. Use Value: Supports full 30B+D channel operation with integrated monitor mode and PRBS diagnostics for SLA verification. |
Use Scenario: Field-deployed RTUs connecting SCADA sensors over long-haul T1 links in utility or transportation networks. IC Role / Device Role / Timing Role: Robust T1 LIU with –36dB receive sensitivity, transmit open-circuit detection, and RCL indication per G.775. Use Value: Maintains link integrity over 6k ft of 22AWG cable while enabling remote loopback and error counting for predictive maintenance. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar line interface unit applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| DS21Q348G | Quad-channel version in 144-ball CSBGA; identical per-channel architecture but shares MCLK and control bus across all four LIUs. | Designed for multi-port line cards where density and inter-channel synchronization matter more than single-channel flexibility. | Select DS21Q348G when building 4×T1/E1 line cards with shared clocking and reduced per-port footprint. |
| DS2155 | Legacy 5V E1/T1 LIU with fixed 120Ω termination; lacks crystal-less jitter attenuator and programmable LBO; only supports parallel interface. | Targeted at cost-sensitive, non-upgradable legacy systems where 3.3V migration or jitter cleanup is not required. | Choose DS2155 only for brownfield replacements where voltage compatibility and minimal firmware changes are mandatory. |
Compared with DS21348G, DS21Q348G offers higher port density and inter-LIU timing coherence at the expense of individual channel configurability, while DS2155 trades modern features (jitter attenuation, flexible termination, 3.3V operation) for backward compatibility in aging 5V infrastructures.
Availability
DS21348G is available at Aetrix Electronics and suitable for telecom infrastructure, channel bank design, CSU/DSX-1 line card development, and ISDN-PRI access node deployment requiring stable component supply and long-term lifecycle support.
Supply support for DS21348G 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) designs precision analog, mixed-signal, and high-reliability semiconductor solutions for communications, industrial, and computing markets.
The DS21348G belongs to Maxim's telecom line interface product line, engineered specifically for carrier-grade E1/T1/J1 physical layer implementation with emphasis on jitter performance, standards compliance, and diagnostic capability.
FAQ
What is the operating temperature range for the DS21348G?
The DS21348G is specified for commercial temperature operation from 0°C to +70°C. This range is confirmed in the Ordering Information table and applies to the 49-ball CSBGA package variant. It is distinct from the industrial-grade DS21348GN (–40°C to +85°C) and should not be substituted in extended-temperature environments without thermal validation.
Does the DS21348G support both E1 and T1 standards simultaneously?
The DS21348G supports E1 and T1 standards, but not simultaneously in a single configuration - the ETS bit (CCR1.7) selects E1 or T1 mode at initialization. Once set, the device configures its receive sensitivity, line build-out, encoding/decoding, and clocking accordingly. Switching standards requires reprogramming registers and adjusting MCLK source if changing between 2.048MHz and 1.544MHz.
Can the DS21348G operate without an external crystal?
Yes, the DS21348G features a crystal-less jitter attenuator that requires only a 2.048MHz master clock (MCLK) for both E1 and T1 operation. A 1.544MHz MCLK may be used optionally for T1-only applications. No external crystal or oscillator is needed for jitter attenuation, simplifying board layout and reducing component count.
What are the key differences between DS21348G and DS21348T?
The DS21348G and DS21348T share identical electrical functionality and pinout but differ in package and temperature grade: DS21348G uses a 49-ball CSBGA (7mm × 7mm) rated for 0°C to +70°C, while DS21348T uses a 44-pin TQFP rated for the same temperature range. The pin numbering differs due to package geometry, but signal mapping (e.g., RTIP, RCLK, MCLK) remains functionally consistent across both variants.
How does the DS21348G handle receive carrier loss detection?
The DS21348G implements G.775-compliant receive carrier loss (RCL) detection via the RCL/LOTC pin. When CCR2.7 = 0 (default in hardware mode), the pin toggles high upon loss of valid signal at RTIP/RRING. This detection is independent of software polling and provides immediate hardware-level fault signaling for system-level alarms and failover logic in the DS21348G.
DS21348G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 49-LFBGA, CSPBGA
- Packaging:
- Tray
- Product Status:
- Obsolete
- Function:
- -
- Interface:
- Serial
- Number of Circuits:
- 1
- Voltage - Supply:
- 3.135V ~ 3.465V
- Current - Supply:
- -
- Power (Watts):
- -
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 49-CSBGA (7x7)
DS21348G FAQ
1.How can I place an order for DS21348G through Aetrix?
Please submit a Request for Quotation (RFQ) for DS21348G 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 DS21348G reliable?
The price and inventory of DS21348G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for DS21348G is usually 5 days.
3.What payment methods are accepted for DS21348G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for DS21348G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for DS21348G?
DS21348G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your DS21348G 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 DS21348G?
For technical support, including DS21348G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your DS21348G requirements.
6.How does Aetrix verify that DS21348G is sourced from the original manufacturer or authorized distributors?
All DS21348G 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 DS21348G meets industry standards.
7.What is the process for return or replacement of DS21348G?
All DS21348G units undergo pre-shipment inspection (PSI). If there is an issue with DS21348G, 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 DS21348G part is unused and in its original packaging.
Return procedure for DS21348G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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