LIN Fail Safe System Basis Chip 20Kbps 32-Pin HTSSOP T/R

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. The fail-safe SBC contains the following integrated devices: In addition to the advantages of integrating these common ECU functions in a single package, the fail-safe SBC offers an intelligent combination of system-specific functions such as: The UJA1069 is designed to be used in combination with a microcontroller and a LIN controller. The fail-safe SBC ensures that the microcontroller is always started up in a defined manner. In failure situations the fail-safe SBC will maintain the microcontroller function for as long as possible, to provide full monitoring and software driven fall-back operation. The UJA1069 is designed for 14 V single power supply architectures and for 14 V and 42 V dual power supply architectures.

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 x 7.8 mm HTSSOP24 package with low thermal resistance
  • Small 8 mm x 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