General description

The SJA1124 is a quad Local Interconnect Network (LIN) master channel device. Each

of the four channels contains a LIN master controller and LIN transceiver with master

termination. LIN master frames are transferred to the physical LIN bus via the LIN

physical layer. The SJA1124 is primarily intended for in-vehicle subnetworks using

baud rates up to 20 kBd and is compliant with LIN 2.0, LIN 2.1, LIN 2.2, LIN 2.2A,

ISO 17987-4:2016(12 V LIN) and SAE J2602-1.

A Serial Peripheral Interface (SPI) and an interrupt output provide the interface between

the SJA1124 and a microcontroller.

Transmit data streams received on the SPI are converted by the SJA1124 into LIN

master frames transmitted on the LIN bus. The LIN master frames are transmitted as

optimized bus signals shaped to minimize ElectroMagnetic Emission (EME). The LIN bus

output pins are pulled HIGH via internal LIN master termination resistors. Data streams

received on the LIN bus input pins can be read by the microcontroller via the SPI.

Power consumption is very low in Low Power mode. However, the SJA1124 can still be

woken up via the LIN pins and the SPI interface.

Features and benefits

2.1 General

• Four LIN master channels:

– LIN master controller

– LIN transceiver

– LIN master termination consisting of a diode and a 1 kΩ ±10 resistor

• Compliant with:

– LIN 2.0, LIN 2.1, LIN 2.2, LIN 2.2A

– ISO 17987-3:2016, ISO 17987-4:2016 (12 V LIN)

– SAE J2602-1

• Very low current consumption in Low Power mode with wake-up via SPI or LIN

• Option to control an external voltage regulator via the INHN output

• Bus signal shaping optimized for baud rates up to 20 kBd

• SPI for communicating with the microcontroller:

– SPI used for configuration, control, diagnosis and LIN data transfer

– Flexible SPI length from 3 bytes to 18 bytes

– Output status pin signals SPI operational state

• Interrupt output pin: interrupts can be configured individually

• Facilitates synchronous LIN frame transmission across multiple SJA1124 devices

• VIO input for direct interfacing with 3.3 V and 5 V microcontrollers

• On-chip Phase-Locked Loop (PLL) for LIN master controller

• Passive behavior in unpowered state

• Undervoltage detection

• Leadless DHVQFN24 package (3.5 mm × 5.5 mm) supporting improved Automated

Optical Inspection (AOI) capability

2.2 LIN master controllers

• Independent per LIN channel:

– Baud rate

– Operating mode

– Status and interrupt

• Complete LIN frame handling and transfer

• One interrupt per LIN frame

• Slave response timeout detection

• Programmable break length

• Automatic sync field generation

• Programmable stop bit length

• Hardware parity generation

• Hardware or software checksum generation

• Fault confinement

• Fractional baud rate generator

2.3 Protection

• Excellent ElectroMagnetic Immunity (EMI)

• Very high ESD robustness: ±6 kV according to IEC61000-4-2 for pins LIN1 to LIN4 and

BAT

• Bus terminal and battery pin protected against transients in the automotive environment

(ISO 7637)

• Bus terminal short-circuit proof to battery and ground

• LIN dominant timeout function

• Thermal protection