System Power IC for Automotive Functional Safety

Toshiba Corporation today announced the launch of the TB9044FNG, a general-purpose system power IC with multiple outputs achieving functional safety for automotive applications. Sample shipments start today, with the mass production scheduled to start in October, 2017. The new IC integrates various failure detection functions, such as high-voltage and low-voltage detection and overheat detection of power supply circuit, to monitor against the IC's own failure, and a watchdog timer to monitor failure detection of the external microcomputer.

An initial diagnosis circuit to detect latent faults in the failure detection circuits is also incorporated to secure higher functional safety. Toshiba has also carried out a range of functional safety analyses to simulate system failures and will provide customers with documentation, such as functional safety FMEDA, to support overall safety analysis and design.

Key features include: Various built-in monitoring circuits for functional safety; Low-voltage detection circuit for battery power supply; High-voltage detection circuit for dc-dc converter (6V); High-voltage / low-voltage detection circuit for series power supply (5V); Overheat detection circuit; Oscillator frequency monitoring circuit; Watchdog timer circuit monitoring the external MCU; Diagnostic circuit for failure detection circuits for functional safety; A built-in diagnostic circuit in the failure-detection circuit detects any latent faults; Built-in buck-boost dc-dc converter; The IC generates 6V output from a high efficiency buck-boost dc-dc converter.; In consideration of voltage drop after idling reduction, the low side operating voltage range is improved down to 2.7V (min.) with battery operation. The IC incorporates four series power supply circuits receiving the 6V input generated by the dc-dc converter.

It also incorporates a circuit with a 5V constant voltage (current capacity is 400mA) for the microcomputer, and three circuits with 5V constant voltage output (current capacity is 100mA) for sensors and other interfaces. Each of them can output a voltage independently. Customers can set the system to respond to detected failures in one of two ways, using the SPI communication input setting. One setting outputs a reset signal to the system; the other provides notification of the abnormal operation to the system. Selection can be made according to the customer’s application or system.