Overview
ISO 11898-2:2024 - Road vehicles - Controller area network (CAN) - Part 2: High‑speed physical medium attachment (PMA) sublayer defines the electrical and functional behaviour of the CAN PMA sublayer. The third edition updates static and dynamic PMA parameters, adds support for new PMA parameter sets (including higher bit‑rate operation), and introduces Annex A for Signal Improvement Capability (SIC) and FAST mode operation. The physical medium dependent (PMD) sublayer is explicitly out of scope.
Key topics and technical requirements
- HS‑PMA function and interfaces: Specification of the AUI (TXD, RXD, GND) and the relationship to the PCS (physical coding sublayer) and PMD. Defines CAN_H / CAN_L signalling for dominant (logical 0) and recessive (logical 1) bus states.
- Static and dynamic parameters: Detailed static limits (voltages, leakage, receiver input resistance) and dynamic behaviours (driver symmetry, transmit timeouts, timing behaviour).
- Low‑power and wake‑up: Requirements for HS‑PMA low‑power modes, basic wake‑up, selective wake‑up and wake‑up patterns (WUP/WUF), and bus biasing procedures.
- SIC and FAST modes (Annex A): Normative support for PMAs with signal‑improvement capability to suppress ringing and for FAST RX/TX modes that change how recessive/level states are driven and detected.
- Conformance and testing: References conformance requirements and cross‑references to CAN test plans (e.g., ISO 16845 series).
- Parameter sets for higher bit rates: Revised parameter set tables include support for implementations above 1 Mbit/s and up to several Mbit/s (new parameter set C introduced).
Applications and who uses it
ISO 11898-2:2024 is essential for:
- Transceiver/chip designers implementing CAN HS‑PMA functionality (normal/low‑power, selective wake‑up, SIC/FAST).
- ECU hardware engineers specifying transceiver requirements and EMC/ESD considerations.
- Automotive system architects integrating CAN networks, including high‑speed CAN XL and partial networking (PN) use cases.
- Test labs and certification bodies performing conformance and interoperability testing against PMA requirements.
- Vehicle OEMs and suppliers adopting higher bit‑rate, low‑power, or SIC‑enabled CAN transceivers for next‑generation in‑vehicle networks.
Related standards
- ISO 11898-1 - CAN data link layer and physical signalling (PCS/AUI definitions)
- ISO 16845 series - CAN conformance test plans
- ISO/IEC 7498-1 - OSI basic reference model (terminology and layer mapping)
ISO 11898-2:2024 is a normative reference for designers and integrators focused on robust, interoperable high‑speed CAN transceivers, low‑power operation, and advanced signal‑integrity modes (SIC/FAST) used in modern automotive networks.
Open preview (PDF)Road vehicles — Controller area network (CAN) — Part 2: High-speed physical medium attachment (PMA) sublayer