Power IC enables designs to meet ASIL-D requirements

The TB9044FNG integrates various failure detection functions, such as a 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 MCU. An initial diagnosis circuit to detect latent faults in the failure detection circuits is also incorporated to secure higher functional safety.

The IC generates a 6V output from a high efficiency buck-boost DC/DC converter. In order to avoid problems following a voltage drop during cranking, the low side operating voltage range is improved down to a minimum of 2.7V with battery operation.

Toshiba has 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.

The IC incorporates four series power supply  output circuits receiving the 6V input generated by the DC/DC converter. It also incorporates an output 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.

Sample shipments start today, with the mass production scheduled to start in October 2017.