Analog Devices Inc./Maxim Integrated DS2148G+

Overview

DS2148G+ from Maxim Integrated is a single-channel, 5V E1/T1/J1 Line Interface Unit (LIU) supporting both short- and long-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 compliance for telecom line interface applications in access multiplexers and channel banks.

For engineers reviewing the DS2148G+ datasheet, DS2148G+ pinout, DS2148G+ application, or DS2148G+ equivalent, this page delivers verified technical context, exact pin functions per CSBGA-49 package, real-world timing roles in E1/T1 framing systems, and validated alternative LIUs for carrier-grade line interface design.

Technical Context

The DS2148G+ integrates full clock/data recovery, AMI/HDB3 (E1) and AMI/B8ZS (T1) encoding/decoding, programmable line build-out (0dB to –22.5dB), and dual-path jitter attenuation configurable into either transmit or receive data paths. It supports 2.048MHz (E1/T1) or optional 1.544MHz (T1) master clock input.

Its analog interface includes transformer-coupled RTIP/RRING inputs with automatic receive sensitivity adjustment (–43dBm E1, –36dBm T1), TTIP/TRING outputs with 50mA RMS current limiting, and NRZ/bipolar data I/O with RCLK-synchronized timing. Hardware mode enables loopback control and alarm generation without host processor intervention.

Key Specifications

Pinout & Package

DS2148G+ uses a 49-ball CSBGA package (7mm × 7mm, RoHS-compliant). Pin assignments are defined for parallel, serial, and hardware modes; all modes share the same physical ball map but assign different functions per mode.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar line interface unit applications.

Compared with DS2148G+, DS21Q48N offers density advantage for multi-port designs but requires larger footprint and higher thermal management, while MAX3005 trades voltage compatibility and jitter performance for lower power - neither is pin-compatible, and DS2148G+ remains optimal for 5V, single-channel, carrier-grade E1/T1 line interface with full G.703 compliance.

Availability

DS2148G+ is available at Aetrix Electronics and suitable for access multiplexers, channel banks, ISDN-PRI terminals, and remote DSLAM shelves requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for DS2148G+ 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 industrial, communications, and computing markets.

The DS2148G+ belongs to Maxim's telecom line interface product line, engineered specifically for carrier-class E1/T1/J1 physical layer termination in access and aggregation equipment with full standards compliance and field-proven reliability.

FAQ

What is the operating temperature range for DS2148G+?

The DS2148G+ is rated for 0°C to +70°C ambient operation. This commercial-grade temperature range aligns with its target applications in controlled-environment telecom infrastructure such as central office shelves and enterprise access nodes. The device uses a 49-ball CSBGA package optimized for thermal dissipation within this range, and all DC/AC specifications in the datasheet are guaranteed across this interval.

Does DS2148G+ support both E1 and T1 standards simultaneously?

Yes, DS2148G+ supports both E1 and T1 standards, but not simultaneously active on the same channel. The ETS bit (CCR1.7) selects E1 (0) or T1 (1) mode at runtime, configuring encoding/decoding (HDB3 vs. B8ZS), line build-out tables, and receive sensitivity ranges accordingly. A single DS2148G+ instance operates in one mode per power cycle, making it suitable for field-upgradable or multi-region deployments.

What clock frequencies does DS2148G+ accept on the MCLK pin?

DS2148G+ accepts a 2.048MHz ±50ppm TTL-level clock on the MCLK pin for both E1 and T1 operation. For T1-only applications, a 1.544MHz ±50ppm clock is optionally supported. The device does not support arbitrary or variable-frequency clocks; MCLK must match one of these two specified rates to ensure correct jitter attenuation, clock/data recovery, and line rate timing.

Can DS2148G+ generate backplane clocks, and what frequencies are available?

Yes, DS2148G+ synthesizes BPCLK from RCLK using an internal divider, offering selectable outputs of 16.384MHz, 8.192MHz, 4.096MHz, or 2.048MHz. These frequencies are derived by dividing RCLK (recovered line clock) by integer factors (1, 2, 4, or 8), enabling synchronous backplane timing for downstream framer or DSP devices without requiring an external clock generator.

How does DS2148G+ handle receive carrier loss detection?

DS2148G+ implements G.775-compliant Receive Carrier Loss (RCL) detection via the RCL/LOTC pin. When enabled (CCR2.7 = 0), the pin asserts high upon loss of valid signal at RTIP/RRING. The device also supports Loss of Transmit Clock (LOTC) detection (CCR2.7 = 1), asserting the same pin if TCLK remains static for >5µs. Both conditions are latched and readable via status registers.