FlexRay Active Star Coupler

TJA1086G Block Diagram

TJA1086G FlexRay™ active coupler device connects two brances of a FlexRay network. It is a dedicated Communication Controller interface allows for integration into an ECU. Also, it is compliant with the FlexRay electrical physical layer specification V3.0.1/ISO17458-4.

The TJA1086G supports low-power management by offering bus wake-up capability along with battery supply and voltage regulator control. Several TJA1085G and TJA1086G devices can be connected via their TRXD0/1 interfaces to increase the number of branches in the network.

Why Used

  • Robustness
    • Bus pins protected against
    • 8 kV ESD pulses according to HBM and 6 kV ESD pulses according to IEC61000-4-2
    • All pins protected against 1000 V ESD according to CDM
    • All pins protected against 200 V ESD according to MM
    • No reverse currents from the digital input pins to VIO or VCC when the TJA1086G is not powered up
    • Bus pins short-circuit proof to battery voltage (14 V, 24 V or 48 V) and ground
    • Overtemperature detection and protection
    • Bus pins protected against transients in automotive environment (according to ISO 7637 class C)
  • Optimized for time-triggered communication systems
    • Compliant with FlexRay Electrical Physical Layer specification V3.0.1/ISO17458-4
    • Automotive product qualification in accordance with AEC-Q100
    • Data transfer rates from 2.5 Mbit/s to 10 Mbit/s
    • Supports 60 ns minimum bit time at 400 mV differential voltage
    • Low-power management for battery-supplied ECUs
    • Very low current consumption in AS_Sleep mode
    • Leadless HVQFN44 package with improved Automated Optical Inspection (AOI) capability
  • Active star functional classes
    • Active star – communication controller interface
    • Active star – bus guardian interface
    • Active star – voltage regulator control
    • Active star – logic level adaptation
    • Active star – host interface
    • Active star – increased voltage amplitude transmitter
  • Functional
    • Supports autonomous active star operation independent of the host ensuring the TJA1086G remains active even if the host fails or is switched off
    • Branches can be independently configured
    • Branch extension via TRXD0/1 inner star interface
    • 16-bit bidirectional SPI interface up to 2 Mbit/s for host communication
    • Full host control over branch status
    • Enhanced wake-up capability:
      • Remote wake-up via wake-up pattern and dedicated FlexRay data frames
      • Local wake-up via pin LWU
      • Wake-up source recognition
      • configurable per branch
    • Enhanced supply voltage monitoring on VIO, VCC, VBUF and VBAT
    • Auto I/O level adaptation to host controller supply voltage VIO
    • Can be used in 14 V, 24 V and 48 V powered systems
    • Enhanced bus error detection – detects short-circuit conditions on the bus
    • Instant transmitter shut-down interface (BGE pin)
    • Selective branch shut-down (partial networking)

Where Used

  • BCMs
  • Gateways

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