General description

The UJA1069 fail-safe System Basis Chip (SBC) replaces basic discrete components which are common in every Electronic Control Unit (ECU) with a Local Interconnect Network (LIN) interface. The fail-safe SBC supports all networking applications which control various power and sensor peripherals by using LIN as a local sub-bus.

Features

General

■ Contains a full set of LIN ECU functions:

◆ LIN transceiver

◆ Voltage regulator for the microcontroller (5.0 V)

◆ Enhanced window watchdog with on-chip oscillator

◆ Serial Peripheral Interface (SPI) for the microcontroller

◆ ECU power management system

◆ Fully integrated autonomous fail-safe system

■ Designed for automotive applications:

◆ Supports 14 V and 42 V architectures

◆ Excellent ElectroMagnetic Compatibility (EMC) performance

◆ ±8 kV ElectroStatic Discharge (ESD) protection Human Body Model (HBM) for off-board pins

◆ ±4 kV ElectroStatic Discharge (ESD) protection IEC 61000-4-2 for off-board pins

◆ ±60 V short-circuit proof LIN-bus pin

◆ Battery and LIN-bus pins are protected against transients in accordance with ISO 7637-3

◆ Very low sleep current

■ Supports remote flash programming via the LIN-bus

■ Available in:

◆ Small 6.4 mm × 7.8 mm HTSSOP24 package with low thermal resistance

◆ Small 8 mm × 11 mm HTSSOP32 package with low thermal resistance

LIN transceiver

■ LIN 2.0 and SAE J2602 compliant LIN transceiver

■ Enhanced error signalling and reporting

■ Downward compatible with LIN 1.3 and the TJA1020

Power management

■ Smart operating modes and power management modes

■ Cyclic wake-up capability in Standby and Sleep mode

■ Local wake-up input with cyclic supply feature

■ Remote wake-up capability via the LIN-bus

■ External voltage regulators can easily be incorporated in the power supply system (flexible and fail-safe)

■ 42 V battery related high-side switch for driving external loads such as relays and wake-up switches

■ Intelligent maskable interrupt output

Fail-safe features

■ Safe and predictable behavior under all conditions

■ Programmable fail-safe coded window and time-out watchdog with on-chip oscillator, guaranteeing autonomous fail-safe system supervision

■ Fail-safe coded 16-bit SPI interface for the microcontroller

■ Global enable pin for the control of safety-critical hardware

■ Detection and detailed reporting of failures:

◆ On-chip oscillator failure and watchdog alerts

◆ Battery and voltage regulator undervoltages

◆ LIN-bus failures (short-circuits)

◆ TXDL and RXDL clamping situations and short-circuits

◆ Clamped or open reset line

◆ SPI message errors

◆ Overtemperature warning

■ Rigorous error handling based on diagnostics

■ Supply failure early warning allows critical data to be stored

■ 23 bits of access-protected RAM is available e.g. for logging of cyclic problems

■ Reporting in a single SPI message; no assembly of multiple SPI frames needed

■ Limp-home output signal for activating application hardware in case system enters Fail-safe mode (e.g. for switching on warning lights)

■ Fail-safe coded activation of Software development mode and Flash mode

■ Unique SPI readable device type identification

■ Software-initiated system reset