Infineon PEF22822F V2.2 ISDN Subscriber Access Controller

The Infineon PEF22822F V2.2 is a communication integrated circuit (IC) belonging to the SIPAC (S/T Interface Subscriber Access Controller) family. It is designed for ISDN (Integrated Services Digital Network) basic rate interfaces (S/T reference point). The device handles the layer 1 (physical) functions of the ISDN S/T bus, including line termination, clock recovery, activation/deactivation, and monitoring. It is commonly used in terminal equipment such as ISDN terminal adapters, router cards, and industrial communication gateways. The IC operates at 5 V and is packaged in a P-TQFP-44 or similar surface-mount package.

Technical Specifications

Supply voltage: 5 V DC ±5%. Current consumption: 50 mA typical. Interface: S/T reference point according to ITU-T I.430. Data rates: 192 kbit/s (basic rate, 2B+D). Frame format: 2 × 64 kbit/s B channels + 16 kbit/s D channel. Operating temperature: -40°C to +85°C (industrial grade). Package: 44-pin TQFP (V2.2 version). Functions: activation/deactivation, D-channel access priority (priority resolution), monitoring of line status, loopback test. The IC interfaces to an external microprocessor via a parallel bus (Intel or Motorola mode). It includes a 16-byte FIFO for D-channel data.

Key Features

• ISDN S/T interface (I.430) for basic rate access

• Full layer 1 (physical) functionality

• Supports point-to-point and point-to-multipoint configurations

• D-channel collision detection and resolution

• Power-down mode

• Parallel microprocessor interface (8-bit)

• Industrial temperature range

• Packaged in TQFP-44

Applications

The PEF22822F is used in legacy ISDN terminal equipment, ISDN primary rate adapters, telecommunications boards, and industrial modems. It may also be used in embedded systems requiring ISDN connectivity for remote monitoring or data transfer over PSTN networks. While ISDN is largely superseded by DSL and fiber, this IC is still encountered in legacy equipment maintenance and retrofits.

Electrical and Timing

The IC requires a 5 V supply. It generates a 4.032 MHz clock output. The S/T interface operates at 192 kbit/s with a bipolar line code (modified AMI). The device includes a timer for activation/deactivation sequences. The microprocessor interface can be set to Intel or Motorola timing via a pin.

Handling and Soldering

The TQFP package is surface-mount; observe ESD precautions. Soldering should follow JEDEC J-STD-020 for moisture sensitivity. Recommended storage temperature: -40°C to +125°C.

Conclusion

The Infineon PEF22822F V2.2 is a specialized IC for ISDN S/T interface applications. It provides complete layer 1 functionality for basic rate access, suitable for telecommunications and industrial communication systems requiring ISDN connectivity.