STMicroelectronics launches first enhanced audio for start/stop and hybrid cars

STMicroelectronics has launched a new series of chips that allow in-car entertainment equipment to operate without interruption as the engine is turned off and restarted in start/stop cars. The first of these is the TDA7850LV, a 4x50W audio power amplifier that is the first start/stop-compatible IC of its kind in production. ST is building a complete family of start/stop audio power amplifiers that will include entry-level class-AB amplifiers, complex digital devices with diagnostic features, and an automotive class-D family offering outstanding power efficiency.

In cars fitted with start/stop, the supply voltage for on-board electrical equipment can fall to as low as 6V when the engine is turned off and restarted and only the battery is supplying electrical power. In addition, switching between battery power and alternator power can generate 'pop and click' noise. Left unaddressed, these effects can cause noticeable distortion in the audio system's output. Hybrid-electric vehicles present similar challenges to electronic equipment designers.

Discrete components external to the audio power amplifier can be used to build circuitry to regulate the supply voltage and suppress pop and click noises. However, these circuits complicate design and add significantly to bill-of-materials costs. ST's TDA7850LV audio power amplifier makes the use of such components unnecessary and therefore simplifies design, reduces cost, and saves pc-board space.

In addition to its start/stop compatibility and high audio performance, the TDA7850LV delivers the advantages of ST's Flexiwatt power package, now the de-facto standard for car audio ICs. A variety of configurations are available, including vertically or horizontally mounted packages. In addition, a unique new surface-mount variant now allows car-audio makers to take advantage of high-speed fully automated assembly enabling increased throughput and production quality.

Major features of the TDA7850LV:

• 4x50W MOSFET output stage
• 2Ω output driver compatible with diverse speaker types Hi-fi class distortion and low output noise, yielding high sound quality
• Integrated 0.35A high-side driver supporting functions such as antenna control Protection against common vehicle electrical hazards such as short circuits to ground and battery, open-circuited speakers, highly inductive loads, load-dump, over-temperature, and electrostatic discharge (ESD).

The TDA7850LV is currently ramping-up mass production, priced at $5.30 for orders of 1000 pieces. Alternative pricing options are available for larger volumes.

For more information visit www.st.com.