The devices support functional safety according to ISO26262 for safety-critical automotive applications including those that require extremely high safety such as electric power steering systems (EPS) and braking systems where ASIL-D is required.
The series comprises of four devices with various output voltages generated by a buck converter - 1.1V (TB9045FNG-110), 1.2V (TB9045FNG-120), 1.25V (TB9045FNG-125), and 1.5V (TB9045FNG-150). The four output voltages from each device can be used to power the core of an MCU, as well as being used for sensors and other interfaces.
A buck-boost converter generates 6V from the automotive battery and is capable of operating with input voltages as low as 2.7V to ensure constant voltage, even during cranking operations when the battery voltage drops significantly. The devices are suited to input voltages as high as 18V and can operate over the temperature range -40 to +125ºC. They are housed in a tiny HTSSOP48-P-300-0.50 package, measuring just 6.1mm × 12.5mm × 1.0mm making them ideal for modern densely packed automotive applications.
The TB9045FNG series includes a range of fault detection features, essential to providing functional safety. This includes over voltage for the DC-DC converter and under voltage lockout (UVLO) for the battery power supply as well as thermal shutdown and a circuit to monitor the oscillator frequency. A watchdog timer is included to detect errors on the external MCU as well as the ability to detect latent faults that would indicate a potential failure. Reporting of any issues can be configured via the SPI interface using a dedicated register, allowing the IC to be used in a wide variety of systems.
To support designers, Toshiba provides a full suite of documentation including a functional safety FMEDA to assist with safety design and analysis of systems.