1 General description

The TJA1445 is a high-speed CAN transceiver that provides an interface between a controller area network

(CAN) or flexible data rate CAN (CAN FD) protocol controller and the physical two-wire CAN bus. TJA1445

transceivers implement the CAN physical layer as defined in ISO 11898-2:2024 and SAE J2284-1 to SAE

J2284-5, making them fully interoperable with high-speed classical CAN and CAN FD transceivers. The

TJA1445 was developed in compliance with ISO 26262, achieving ASIL B.

The TJA1445 features very low power consumption in Standby and Sleep modes. It supports CAN partial

networking by means of selective wake-up functionality as specified in ISO 11898-2:2024, making the TJA1445

the ideal choice for CAN system implementations where only nodes that are needed are to be activated.

Nodes that are not needed for the function being performed can be powered down to minimize system power

consumption, even when CAN bus traffic is running.

The TJA1445 includes an SPI for configuration, mode control and diagnostics. The TJA1445B additionally

features three general-purpose I/O pins (GPIO) and a CAN transmitter enable/disable input.

The TJA1445 can be configured to ignore CAN FD frames while waiting for a valid wake-up frame. This

additional feature of partial networking, called CAN FD passive, is the perfect fit for networks that support a mix

of classical CAN and CAN FD communication.

2 Features and benefits

2.1 General

• ISO 11898-2:2024 parameter sets A-B, SAE J2284-1 to SAE J2284-5 and SAE J1939-14 compliant

• ISO 26262, ASIL B compliant

• Partial networking capability through selective wake-up functionality

• Configurable general-purpose I/O (GPIO) pins (TJA1445B)

• Second RXD and/or TXD pins (RXD2/TXD2), configurable via GPIO (TJA1445B)

• Direct transmitter on/off control input (TXEN_N) (TJA1445B)

• Autonomous bus biasing

• Low electromagnetic emission (EME) and high electromagnetic immunity (EMI)

• Qualified according to AEC-Q100 Grade 1

• VIO input for interfacing with 1.8 V, 3.3 V to 5 V microcontrollers

• ListenOnly mode for node diagnosis and failure containment

• TJA1445A available in an SO14 package and leadless HVSON14 package with automatic optical inspection

(AOI) capabilities

• TJA1445B available in a DHVQFN18 package with automatic optical inspection (AOI) capabilities

• Dark green product (halogen free and restriction of hazardous substances (RoHS) compliant)

• Selectable interrupts on RXD; option to signal only wake-up and power-on related interrupts or all interrupts

• 4-byte general-purpose memory

• SPI system reset

• End-of-line microcontroller flashing support through CAN pins

• Selectable WAKE pin filter time

2.2 Predictable and fail-safe behavior

• Undervoltage detection on all supply pins with defined behavior below the undervoltage thresholds

• Functionality guaranteed from the undervoltage detection thresholds up to the maximum limiting voltage

values

• Transceiver disengages from the bus (high-ohmic) when the battery voltage drops below the Off mode

threshold

• Internal biasing of TXD to enable defined fail-safe behavior

2.3 Low-power management

• Very low-current Standby and Sleep modes, with local and remote wake-up capability

• Local wake-up via the WAKE pin

• Remote wake-up via a wake-up pattern (WUP) or wake-up frame (WUF)

• Configurable CAN wake-up pattern (dom-rec-dom or dom-rec-dom-rec) according to ISO 11898-2:2024.

• Selective wake-up according to ISO 11898-2:2024

• Entire node containing the TJA1445 can be powered down via INH while still supporting local and remote

wake-up

• Only VBAT is needed to support local and remote wake-up

• Support for pretended networking through low-power ListenOnly mode

2.4 Diagnosis and Protection

• Overtemperature diagnosis and protection

• Transmit data (TXD) dominant time-out diagnosis and protection

• Bus dominant failure diagnosis

• Cold start diagnosis (first battery connection)

• High ESD handling capability on the bus pins

• Bus pins and VBAT protected against automotive transients