NXP UJA1076ATW/3V3WD,1

The UJA1076A core System Basis Chip (SBC) replaces the basic discrete components commonly found in Electronic Control Units (ECU) with a high-speed Controller Area Network (CAN). The UJA1076A supports the networking applications used to control power and sensor peripherals by using a high-speed CAN as the main network interface. The core SBC contains the following integrated devices:

• High-speed CAN transceiver, inter-operable and downward compatible with CAN transceiver TJA1042, and compatible with the ISO 11898-2 and ISO 11898-5 standards
• Advanced independent watchdog (UJA1076A/xx/WD versions)
• 250 mA voltage regulator for supplying a microcontroller; extendable with external PNP transistor for increased current capability and dissipation distribution
• Separate voltage regulator for supplying the on-board CAN transceiver
• Serial Peripheral Interface (SPI) (full duplex)
• 2 local wake-up input ports
• Limp-home output port

In addition to the advantages gained from integrating these common ECU functions in a single package, the core SBC offers an intelligent combination of system-specific functions such as:

• Advanced low-power concept
• Safe and controlled system start-up behavior
• Detailed status reporting on system and sub-system levels

The UJA1076A is designed to be used in combination with a microcontroller that incorporates a CAN controller. The SBC ensures that the microcontroller always starts up in a controlled manner.

• Contains a full set of CAN ECU functions:
  • CAN transceiver
  • Scalable 3.3 V or 5 V voltage regulator delivering up to 250 mA for a microcontroller and peripheral circuitry; an external PNP transistor can be connected for better heat distribution over the PCB
  • Separate voltage regulator for the CAN transceiver (5 V)
  • Watchdog with Window and Timeout modes and on-chip oscillator
  • Serial Peripheral Interface (SPI) for communicating with the microcontroller
  • ECU power management system
• Designed for automotive applications:
  • Enhanced ElectroMagnetic Compatibility (EMC) performance
  • ±8 kV ElectroStatic Discharge (ESD) protection Human Body Model (HBM) on the CAN bus pins and the wake-up pins
  • ±6 kV ElectroStatic Discharge (ESD) protection IEC 61000-4-2 on the CAN bus pins and the wake-up pins
  • ±58 V short-circuit proof CAN bus pins
  • Battery and CAN bus pins are protected against transients in accordance with ISO 7637-3
• Supports remote flash programming via the CAN bus
• Small 6.1 mm×11 mm HTSSOP32 package with low thermal resistance
• Pb-free; Restriction of Hazardous Substances Directive (RoHS) and dark green compliant
• ISO 11898-2 and ISO 11898-5 compliant high-speed CAN transceiver
• Dedicated low dropout voltage regulator for the CAN bus:
  • Independent of the microcontroller supply
  • Significantly improves EMC performance
• Bus connections are truly floating when power is off
• SPLIT output pin for stabilizing the recessive bus level
• Wake-up via CAN or local wake-up pins with wake-up source detection
• 2 wake-up pins:
  • WAKE1 and WAKE2 inputs can be switched off to reduce current flow
  • Output signal (WBIAS) to bias the wake-up pins, selectable sampling time of 16 ms or 64 ms
• Standby mode with very low standby current and full wake-up capability; V1 active to maintain supply to the microcontroller
• Sleep mode with very low sleep current and full wake-up capability
• Safe and predictable behavior under all conditions
• Programmable watchdog with independent clock source:
  • Window, Timeout (with optional cyclic wake-up) and Off modes supported (with automatic re-enable in the event of an interrupt)
• 16-bit Serial Peripheral Interface (SPI) for configuration, control and diagnosis
• Global enable output for controlling safety-critical hardware
• Limp home output (LIMP) for activating application-specific ‘limp home’ hardware in the event of a serious system malfunction
• Overtemperature shutdown
• Interrupt output pin; interrupts can be individually configured to signal V1/V2 undervoltage, CAN/local wake-up and cyclic and power-on interrupt events
• Bidirectional reset pin with variable power-on reset length to support a variety of microcontrollers
• Software-initiated system reset
• Main voltage regulator V1:
  • Scalable voltage regulator for the microcontroller, its peripherals and additional external transceivers
  • ±2 % accuracy, 3.3 V and 5 V versions available
  • Delivers up to 250 mA and can be combined with an external PNP transistor for better heat distribution over the PCB
  • Selectable current threshold at which the external PNP transistor starts to deliver current
  • Undervoltage warning at 90 % of nominal output voltage and undervoltage reset at 90 % or 70 % of nominal output voltage
  • Can operate at V_BAT voltages down to 4.5 V (e.g. during cranking), in accordance with ISO 7637 pulse 4/4b and ISO 16750-2
  • Stable output under all conditions
• Voltage regulator V2 for CAN transceiver:
  • Dedicated voltage regulator for on-chip high-speed CAN transceiver
  • Undervoltage warning at 90 % of nominal output voltage
  • Can be switched off; CAN transceiver can be supplied by V1 or by an external voltage regulator
  • Can operate at V_BAT voltages down to 5.5 V (e.g. during cranking) in accordance with ISO 7637, pulse 4
  • Stable output under all conditions