System-basis-chip enhances automotive monitoring functions

The increasing importance of ISO 26262, the international standard for “Road Vehicles – Functional Safety”, requires monitoring of the functions of power supply ICs. Reducing power consumption, the IC features built-in highly electrically efficient DC-DC converters and its series regulators realize low noise power supplies.

The TB9042FTG incorporates one DC-DC converter to step down the power supply from the vehicle battery to 6V, and the other converter to step that down to 1.2V or 1.5V (selectable) for the microcontroller core.Two series regulators convert the 6V supply from the DC-DC converter and independently provide constant 5V supplies: 400mA current capacity is used for the microcontroller, and 100mA current capacity is used for a sensor or other interface.

Used as back-up power supply to protect the microcontroller’s RAM data, the other series regulator takes power from the battery and supplies 5V or 3.3V power (selectable). The TB9042FTG incorporates abnormality detection for each output and transmits the detected data from either the SPI terminal or a special terminal dedicated to abnormality signals. Integrated diagnostic functionality monitors for IC malfunction by comparing its data and signals from a microcontroller, helping to realize automotive functional safety.

Operating over a wide temperature range of -40°C to +125°C and featuring a variety of built-in monitoring and detecting functions for safety, the TB9042FTG features: built-in 2-channel DC-DC converters, built-in 3-channel LDOs, stand-by current of 250μA (max), and an operating voltage range of +7.0 to 20.1V.

Sampling now, the TB9042FTG is in a HQFN52 (8mm x 8mm x 0.9mm) package will be produced in volume productions of 2 million pieces per year from May 2014.