Next-generation audio amplifier that maintains Hi-Fi sound even when the engine is stopped or running

As automotive manufacturers introduce features such as engine start/stop to reduce fuel consumption and carbon emissions, STMicroelectronics ( www.st.com , Country Manager for Korea Sung-keun Kang), a global leader in automotive ICs, is developing next-generation advanced chips that ensure in-vehicle entertainment devices do not stop operating even during engine stop and restart. As the first product among these, it has launched the TDA7850LV, a 4x50W audio power amplifier, the industry's first start/stop compatible IC.

Some manufacturers anticipate that technologies such as start/stop and high-efficiency engine management programs will reduce energy and fuel consumption in specific car models by up to 20% over the next few years. For example, start/stop systems stop the engine when the driver stops at a traffic signal and restart it when the vehicle moves again. According to market analysis firm Strategy Analytics, annual demand for vehicles equipped with start/stop features is projected to reach approximately 20 million units by 2015, initially driven by the European region.

When a vehicle is equipped with a start/stop function, the supply voltage of on-board electronic devices can drop to as low as 6V when the engine is restarted after stopping and power is supplied solely by the battery. Furthermore, 'pop-and-click' noises may occur when switching from battery power to alternator power. If these issues are not resolved, noticeable distortion may occur in the audio system output. Hybrid-electric vehicles present these technical challenges to electronic device designers.

By using discrete components mounted externally to the audio power amplifier, it is possible to build a circuit that regulates the supply voltage and suppresses pop-and-click noise. However, in this case, the design becomes complex and significant BOM (bill-of-material) costs are incurred. ST's TDA7850LV audio power amplifier eliminates the need for these discrete components, thereby simplifying the design, lowering costs, and saving PCB space.

ST has a complete family of start/stop audio power amplifiers consisting of simple Class-AB amplifiers, complex digital devices providing diagnostic functions, and automotive Class-D product families offering excellent power efficiency characteristics.

Fabio Marchio, Vice President of ST’s Automotive Products Group and General Manager of the Automotive Infotainment Business Unit, stated, “The new product family, led by the TDA7850LV, integrates the high-fidelity audio performance and exceptional robustness of audio power ICs—where ST has consistently led the industry—with advanced start/stop performance. We [support] our customers’ eco-friendly systems