Toshiba Corporation announced the launch of “TB9044FNG”, a general-purpose system power IC with multiple outputs achieving functional safety for automotive applications. The IC finds applications in safety-critical automotive systems, such as electric power steering (EPS) and braking, which are required to meet the requirements of ASIL-D, the highest automotive safety integrity level prescribed in the ISO 26262 functional safety standards.
The IC incorporates various built-in monitoring circuits for functional safety including a low-voltage detection circuit for battery power supply, a high-voltage detection circuit for DC-DC converter (6V), a high-voltage / low-voltage detection circuit for series power supply (5V), an overheat detection circuit, an oscillator frequency monitoring circuit and a watchdog timer circuit monitoring the external MCU. Additionally, a built-in diagnostic circuit in the failure-detection circuit detects any latent faults.
From an in-built high-efficiency buck-boost DC-DC converter, the IC generates 6V output. 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 device 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.
Additionally, the IC provides selectable operation for failure detections. 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.
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.