ICs with enhanced monitoring functions contribute to automotive functional safety

October 29, 2013 // By Christoph Hammerschmidt
Toshiba Electronics Europe (TEE) has launched a multi-output system power supply IC that enhances monitoring functions in general automotive applications. Samples of the TB9042FTG will be available from November 2013, with mass production scheduled to start in May 2014.

The increasing importance of ISO 26262, the international standard for “Road Vehicles – Functional Safety”, requires monitoring of the functions of power supply ICs. The TB9042FTG incorporates multiple monitoring functions that detect any malfunctions of the IC and external microcontrollers. It also integrates a transmitting function that transfers data on monitoring status to an external microcontroller, which further supports improved safety.

Increasingly higher current is required for automotive applications. The efficient DC-DC converters integrated into these new ICs educe power consumption, and its series regulators realize low noise power supplies.

The chips contain two channels of DC/DC converters. One converter steps down the power supply from the vehicle battery to 6V; the other one steps this voltage level down to 1.2V or 1.5V (selectable) for the microcontroller core.

Two built-in 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. A further series regulator takes power from the battery and supplies 5V or 3.3V power (selectable), which is used as back-up power supply to protect the microcontroller's RAM data.

The product incorporates abnormality detection for each output and transmits the detected data from either the SPI terminal or a special terminal dedicated to abnormality signals. An integrated diagnostic function monitors for IC malfunction by comparing its data and signals from a microcontroller, helping to realize automotive functional safety. This combination of functional building blocks enables designers to implement a variety of safety-related monitoring functions within vehicles.

For more information visit www.toshiba-components.com.