Infineon Technologies SAB82526N-V21

Overview

SAB82526N-V21 from Siemens AG is a single-channel High-Level Serial Communication Controller Extended (HSCX) IC implementing HDLC/LAPB/LAPD/SDLC layer-2 protocol handling, featuring 64-byte TX/RX FIFOs, on-chip DPLL clock recovery per channel, and support for up to 4 Mbit/s data rates in telecom and ISDN terminal equipment.

For engineers reviewing the SAB82526N-V21 datasheet, SAB82526N-V21 pinout, SAB82526N-V21 application, or SAB82526N-V21 equivalent, key selection criteria include its single-HDLC-channel architecture, P-LCC-44 package compatibility with SAB82525, Intel/Motorola 8-bit bus interface timing, and programmable time-slot assignment for TDM systems.

Technical Context

The SAB82526N-V21 implements a dedicated HDLC data link controller with autonomous flag detection, bit stuffing, CRC-16 generation/checking, and address field recognition - all executed without CPU intervention. It supports LAPB (X.25), LAPD (ISDN D-channel), and SDLC-NRM protocols in Auto-Mode via configurable modulo-8 or modulo-128 frame sequencing.

Its serial interface includes independent Rx/Tx clock inputs per channel, dual baudrate generators (one active), and DPLL-based clock recovery enabling stable operation with jittered or unframed line clocks. The 8-bit demultiplexed bus interface operates at up to 4 MHz with ALE/IM0/IM1 control signals for seamless integration into 8/16-bit microprocessor systems.

Key Specifications

Pinout & Package

Package: P-LCC-44 (plastic leaded chip carrier, 44-pin, surface-mount, JEDEC MO-115AA compliant).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SAB82525N and Z8536, SAB82526N-V21 delivers optimal balance of single-channel efficiency, integrated DPLL, and telecom-specific features like programmable time-slot length - making it uniquely suited for ISDN terminal and TDM edge devices where channel count, clock autonomy, and timing precision are critical.

Availability

SAB82526N-V21 is available at Aetrix Electronics and suitable for ISDN terminal adapters, PCM multiplexers, industrial protocol gateways, and legacy modem interface cards requiring stable component supply and long-term lifecycle support.

Supply support for SAB82526N-V21 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 Semiconductor Group (now Infineon Technologies) was a leading European semiconductor manufacturer specializing in industrial, automotive, and telecom ICs before spinning off its chip business in 1999.

The SAB82526 belongs to the HSCX product line, designed specifically for high-reliability serial communications in ISDN, PCM, and packet-switched network equipment - emphasizing autonomous protocol handling and minimal host CPU dependency.

FAQ

Is SAB82526N-V21 pin-compatible with SAB82525N?

Yes, SAB82526N-V21 is fully pin- and software-compatible with SAB82525N in P-LCC-44 packaging. Channel A pins (e.g., TxDA, RxDA, DRQRA) are no-connect, while all Channel B and shared control signals (INT, CS, D0–D7, etc.) occupy identical positions. This allows drop-in replacement where only one HDLC channel is required.

Does SAB82526N-V21 require an external crystal?

No - the device supports both external clock input (via RxCLKB/TxCLKB) and internal quartz oscillator circuitry (requiring only a 3.579545 MHz or 4.096 MHz crystal connected to OSC1/OSC2 pins). The on-chip DPLL then recovers clean bit clocks from noisy line sources, eliminating need for external clock conditioning.

What is the maximum supported HDLC frame size?

The SAB82526N-V21 supports programmable maximum packet sizes up to 65,535 bytes via the MAXLEN register. However, practical limits are constrained by the 64-byte FIFO depth and host DMA transfer size; typical implementations use 32-byte blocks aligned to the FIFO boundary for optimal throughput and latency.

Can SAB82526N-V21 operate in half-duplex SDLC mode?

Yes - the device supports SDLC Normal Response Mode (NRM) in both half-duplex and full-duplex configurations. In half-duplex mode, it uses RTSB/CTSB handshaking to coordinate transmit/receive switching, and handles poll/response sequences, frame retransmission, and modulo-8 or modulo-128 sequence numbering entirely in hardware.