Mini High-Speed CAN System Basis Chip for Partial Networking

The UJA1168 is a mini high-speed CAN System Basis Chip (SBC) containing an ISO 11898-2/5/6 compliant HS-CAN transceiver and an integrated 5 V/100 mA supply for a microcontroller. It also features a watchdog and a Serial Peripheral Interface (SPI). The UJA1168 can be operated in very low-current Standby and Sleep modes with bus and local wake-up capability and supports ISO 11898-6 compliant CAN partial networking by means of a selective wake-up function. The microcontroller supply is switched off in Sleep mode. The UJA1168TK and UJA1168TK/FD versions contain a battery-related high-voltage output (INH) for controlling an external voltage regulator, while the UJA1168TK/VX and UJA1168TK/VX/FD are equipped with a 5 V sensor supply (VEXT).

A dedicated implementation of the partial networking protocol has been embedded into the UJA1168/FD variants, UJA1168TK/FD and UJA1168TK/VX/FD. This function is called ‘FD-passive’ and is the ability to ignore CAN FD frames while waiting for a valid wake-up frame in Sleep/Standby mode. This additional feature of partial networking is a good fit for networks that support both CAN FD and standard CAN 2.0 communications. It allows normal CAN controllers that do not need to communicate CAN FD messages to remain in partial networking Sleep/Standby mode during CAN FD communication without generating bus errors.

The UJA1168 implements the standard CAN physical layer as defined in the current ISO11898 standard (-2, -5 and -6). Pending the release of the updated version of ISO11898 including CAN FD, additional timing parameters defining loop delay symmetry are included. This implementation enables reliable communication in the CAN FD fast phase at data rates up to 2 Mbit/s.

A number of configuration settings are stored in non-volatile memory, allowing the SBC to be adapted for use in a specific application. This makes it possible to configure the power-on behavior of the UJA1168 to meet the requirements of different applications.