General description

The UJA113xA System Basis Chip (SBC) contains a fully integrated buck and boost converter along with a

number of features commonly found in the latest generation of automotive Electronic Control Units (ECUs). It

interfaces directly with CAN and LIN bus lines, supplies the microcontroller, handles input and output signals

and supports fail-safe features including a watchdog and advanced ‘limp home’ functionality configurable via

non-volatile memory. The UJA113xA is available in number of variants as detailed in Section 3.

To satisfy the demand for SBCs that operate at low battery supply voltages and feature low power dissipation,

a switched mode power supply (SMPS) with automatic down (Buck mode) or up conversion (Boost mode)

has been integrated into the UJA113xA. In Boost mode, the SMPS of the UJA1131A and UJA1132A variants

can continue supplying a microcontroller during dips in the battery voltage, ensuring uninterrupted operation.

The boost stage of the UJA1135A and the UJA1136A has limited output current capability, and is suitable for

supplying the memory in a microcontroller to prevent information being lost. The SMPS requires only a single

external coil and some capacitors but no separate semiconductors.

The UJA113xA implements the standard CAN physical layer as defined in ISO 11898-2:2016. This

implementation enables reliable communication in the CAN FD fast phase at data rates up to 5 Mbit/s.

The UJA113xAHW/xFx variants support ISO 11898-2:2016 compliant CAN partial networking with a selective

wake-up function incorporating CAN FD-passive. CAN FD-passive is a feature that allows CAN FD bus traffic

to be ignored in Sleep/Standby mode. CAN FD-passive partial networking is the perfect fit for networks that

support both CAN FD and classic CAN communications. It allows normal CAN controllers that do not need

to communicate CAN FD messages to remain in partial networking Sleep/Standby mode during CAN FD

communication without generating bus errors.

A number of configuration settings are stored in non-volatile memory. This makes it possible to adapt the poweron and limp home behavior of the UJA113xA to meet the specific requirements of an application

Features and benefits

2.1 General

• Generic SBC functions:

– Fully integrated buck-boost converter

– 5 V/3.3 V voltage regulator delivering up to 500 mA

– Separate voltage regulator with optional protection against shorts to battery and loss of module ground

– CAN transceiver and up to two LIN transceivers

– Two-channel battery monitoring with integrated A/D converter

– Watchdog with Window and Timeout modes and on-chip oscillator

– Serial Peripheral Interface (SPI) for communicating with the microcontroller

– ECU power management system

– Protected general-purpose high-voltage I/O pins configurable as high-side drivers (HS), low-side drivers

(LS) or wake-up inputs

– Four internal PWM/pulse timers in derivatives containing high-voltage I/O pins

(see Table 1)

• Qualified for use in road vehicles with a nominal 12 V system:

– Excellent ElectroMagnetic Compatibility (EMC) performance

– ±6 kV ElectroStatic Discharge (ESD) protection according to the Human Body Model (HBM) on the CAN/LIN

bus pins

– ±6 kV ESD protection according to IEC 61000-4-2 on the CAN/LIN bus pins, the sensor supply output

(VEXT) and the HVIO pins

– ±40 V short-circuit proof CAN/LIN bus pins

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

– Very low-current Standby and Sleep modes with full wake-up capability

• Supports remote flash programming via the CAN-bus

• Compact 10 mm × 10 mm HTQFP48 package with low thermal resistance

• Dark green product (halogen free and Restriction of Hazardous Substances (RoHS) compliant)

• Hardware and software compatible with the UJA113x product family

2.2 Integrated buck and boost converter (SMPS)

• Buck and boost functions with a single external coil:

– Automatic Buck or Boost mode selection depending on input voltage and output load conditions

– Boost function allows the UJA1131A and UJA1132A to operate at very low supply voltages (e.g. 2 V; lowest

achievable supply voltage depends on output load conditions)

– Boost function of the UJA1135A and UJA1136A can be used to supply the volatile memory of a

microcontroller down to battery voltages as low as 2 V

– Soft-start function

• The SMPS functions as a pre-regulator for V1 and, optionally, V2:

– Results in excellent load response at V1 and V2

– Results in negligible ripple at V1 and V2 outputs

– Pre-regulator output voltage selectable via the SPI

– The SMPS can be switched to Pass-through mode to ensure the lowest possible

current consumption with immediate full output current capability

• The SMPS can be used to supply external loads directly:

– e.g. as an energy-efficient supply for an LED chain

Low-drop voltage regulators (LDOs)

• Main voltage regulator V1:

– 5 V or 3.3 V nominal output voltage (depending on the selected device)

– 500 mA output current capability

– capable of 500 mA transient load current jump in Standby mode

– Current limiting above 500 mA

– On-resistance of less than 2 Ω

– ±2 % accuracy

– Undervoltage reset; selectable threshold on the 5 V version: 60 %, 70 %, 80 % or 90 % of nominal value

(default detection and release at 90 %)

– Excellent transient response with a small ceramic output capacitor

– Short-circuit protection

– Integrated clamp protects the microcontroller by maintaining the output voltage below 6 V, even when

reverse currents of up to 50 mA are injected

– Turned off in Sleep mode

• Auxiliary voltage regulator V2 with configurable output stage:

– 5 V nominal output voltage

– ±2 % accuracy (±1.5 % up to 5 mA output current)

– Excellent transient response with a small ceramic output capacitor

– Short-circuit protection

– Current limiting above 100 mA

– Configurable as supply for on-board loads

– Configurable as supply for off-board loads (‘sensor supply’); protected against shorts to GND and battery; loss-of-ground proof; high ESD robustness

CAN transceiver

• ISO 11898-2:2016 and SAE J2284-1 to SAE J2284-5 compliant high-speed CAN transceiver supporting CAN

FD active communication up to 5 Mbit/s in the CAN FD data field

• Autonomous bus biasing according to ISO 11898-2:2016

• CAN-bus connections are truly floating when power to pin BAT is off

• UJA113xAHW/xFx: ISO 11898-2:2016 compliant selective wake-up frame detection

– No ‘false’ wake-ups due to CAN FD traffic

– Bit rates of 50 kbit/s, 100 kbit/s, 125 kbit/s, 250 kbit/s, 500 kbit/s and 1 Mbit/s supported during selective wake-up

• Separate supply pin for flexibility (e.g. can be supplied from V1 or V2)

LIN transceivers

• One or two channels depending on the selected device

• LIN2.x and ISO 17987-4:2016 (12 V LIN) compliant

• Compliant with SAE J2602

• Downward compatible with LIN 1.3

• Integrated LIN responder termination

• Improved EMC emission performance with optimized curve shaping