Highly integrated boost converter for stop-start applications reduces fuel consumption by up to 15 percent

March 22, 2012 // By Paul Buckley
International Rectifier has introduced an automotive-qualified AUIR3240S battery power switch for the combustion-engine shut-off and restart function (Stop-Start system) that can help reduce fuel consumption in automotive vehicles by up to 15 percent.

The AUIR3240S is a highly integrated boost converter designed specifically for the Stop-Start system that halts the engine when a vehicle is stopped in traffic. This system requires a ‘board net stabilizer’ using a power switch that disconnects the starter and main battery from the auxiliary electrical systems during engine start. The AUIR3240S is capable of driving several MOSFETs in parallel to achieve very low on-state resistance (Rds(on)) with current consumption below 50 µA. The new device provides 15 V on the output with a wide input voltage (4-36 V). The AUIR3240S also features diagnostic on the output current and a thermal sensor interface for robust designs.

The AUIR3240S is qualified according to AEC-Q100 standards, features an environmentally friendly, lead-free and RoHS compliant bill of materials, and is part of IR’s automotive quality initiative targeting zero defects.

Availability and Pricing

Pricing for the AUIR3240S begins at US $0.85 each in 100,000-unit quantities. Production orders are available immediately.

More information about the AUIR3240S battery power switch at