Infineon Technologies SAB 82526 H V2.2

Overview

SAB 82526 H V2.2 from Siemens AG is a single-channel High-Level Serial Communication Controller Extended (HSCX) IC implementing HDLC Layer-2 protocol handling with integrated DPLL clock recovery, 64-byte TX/RX FIFOs, and DMA/interrupt data transfer - designed for ISDN LAPD, X.25 LAPB, and SDLC-NRM applications in telecom infrastructure and industrial serial gateways.

For engineers reviewing the SAB 82526 H V2.2 datasheet, SAB 82526 H V2.2 pinout, SAB 82526 H V2.2 application, or SAB 82526 H V2.2 equivalent, this controller delivers deterministic frame processing, programmable time-slot assignment (1–256 bits), and 4 Mbit/s serial throughput with minimal CPU intervention via its 8-bit demultiplexed bus interface and dual DMA request lines.

Technical Context

The SAB 82526 H V2.2 implements one full-duplex HDLC channel (Channel B only), supporting auto-mode (LAPB/LAPD/SDLC), non-auto mode, and multiple transparent modes with bit-stuffing, CRC-16 generation/checking, flag detection, and address field recognition fully offloaded from host CPU. It integrates a dedicated DPLL per channel for robust clock recovery from NRZ-encoded serial streams.

Its register-mapped interface includes 8-bit demultiplexed bus timing compatible with Intel 80C86/80C88 and Motorola 68000 families, with separate TxCLKB/RxCLKB/AxCLKB signals, DRQTB/DRQRB/DACKB control lines, and programmable timeout/retry conditions for link-layer reliability.

Key Specifications

Pinout & Package

Package: P-MQFP-44-2 (SMD), 44-pin plastic metric quad flat pack with 0.8 mm lead pitch and exposed thermal pad.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar HDLC controller applications.

Compared with SAB 82525 N, the SAB 82526 H V2.2 reduces pin count and power by removing Channel A, simplifying layout in single-link designs; versus Z8536, it eliminates external clock recovery components but requires tighter timing alignment on RxCLKB.

Availability

SAB 82526 H V2.2 is available at Aetrix Electronics and suitable for ISDN terminal adapters, industrial protocol gateways, and packet-switched router nodes requiring stable component supply, long-lifecycle support, and proven telecom-grade reliability.

Supply support for SAB 82526 H V2.2 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

Siemens AG (now Infineon Technologies) was a German semiconductor pioneer, developing high-reliability ICs for industrial automation, telecommunications, and automotive systems before spinning off its chip division in 1999.

The SAB 82526 belongs to Siemens' High-Level Serial Communication Controller Extended (HSCX) product line, engineered specifically for carrier-class ISDN, X.25, and TDM infrastructure where deterministic Layer-2 offload and clock recovery integrity are critical.

FAQ

What is the function of the AxCLKB pin on the SAB 82526 H V2.2?

AxCLKB serves as the auxiliary clock input for the Channel B DPLL, enabling precise clock recovery from noisy or jittery serial streams. It operates independently from RxCLKB and TxCLKB, allowing the DPLL to lock onto an external reference or derived timing signal for improved stability in E1/PCM environments.

Does the SAB 82526 H V2.2 support both LAPB and LAPD protocols simultaneously?

No - it supports either LAPB (X.25) or LAPD (ISDN) per channel depending on mode configuration, but not both concurrently. Channel B operates in auto-mode with programmable protocol selection via register writes; LAPD requires specific SAPI/TEI addressing setup, while LAPB uses modulo-8 or modulo-128 sequence numbering.

Can the SAB 82526 H V2.2 operate without an external crystal?

Yes - it supports both external clock input (via AxCLKB) and on-chip quartz oscillator circuitry (requiring external 3.579545 MHz or 4.096 MHz crystal between OSC1/OSC2 pins). The DPLL can recover clock from serial data even without crystal, but oscillator mode is required for master clock generation in transmit-only configurations.

How does the Receive Length Check feature prevent buffer overflow?

The Receive Length Check compares incoming frame length against a user-programmed MAXLEN register value after CRC validation. If exceeded, the HSCX discards the frame, asserts an error interrupt, and clears the RX FIFO - preventing malformed or oversized packets from corrupting host memory buffers during DMA transfers.