General description

The TJA1081 is a FlexRay node transceiver that is fully compliant with the FlexRay electrical physical layer specification V2.1 Rev. A (see Ref. 1) and partly complies with versions V2.1 Rev. B. In addition, the TJA1081 already incorporates features and parameters anticipated to be included in V3.0, currently being finalized. It is primarily intended for communication systems from 1 Mbit/s to 10 Mbit/s, and provides an advanced interface between the protocol controller and the physical bus in a FlexRay network.

The TJA1081 features enhanced low-power modes, optimized for ECUs that are permanently connected to the battery.

Features

2.1 Optimized for time triggered communication systems

■ Compliant with FlexRay electrical physical layer specification V2.1 Rev. A (see Ref. 1)

■ Automotive product qualification in accordance with AEC-Q100

■ Data transfer up to 10 Mbit/s

■ Support of 60 ns minimum bit time

■ Very low ElectroMagnetic Emission (EME) to support unshielded cable

■ Differential receiver with wide common-mode range for high ElectroMagnetic Immunity (EMI)

■ Auto I/O level adaptation to host controller supply voltage VIO

■ Can be used in 14 V and 42 V powered systems

■ Bus guardian interface

■ Independent power supply ramp-up for VBAT, VCC and VIO

2.2 Low power management

■ Low power management including inhibit switch

■ Very low current in Sleep and Standby modes

■ Local and remote wake-up

■ Supports remote wake-up via dedicated data frames

■ Wake-up source recognition

2.3 Diagnosis (detection and signalling)

■ Overtemperature detection

■ Short-circuit on bus lines

■ VBAT power-on flag (first battery connection and cold start)

■ Pin TXEN and pin BGE clamping

■ Undervoltage detection on pins VBAT, VCC and VIO

■ Wake source indication

2.4 Protections

■ Bus pins protected against ±8 kV HBM ESD pulses

■ Bus pins protected against transients in automotive environment (ISO 7637 class C compliant)

■ Bus pins short-circuit proof to battery voltage (14 V and 42 V) and ground

■ Fail-silent behavior in the event of an undervoltage on pins VBAT, VCC or VIO

■ Passive behavior of bus lines while the transceiver is not powered

2.5 Functional classes according to FlexRay electrical physical layer specification (see Ref. 1)

■ Bus driver voltage regulator control

■ Bus driver - bus guardian control interface

■ Bus driver logic level adaptation