Given its importance to the car-buying driver, it should be no surprise that consumer expectations are high and, as a result, designers of these systems are being challenged to deliver ever-improved performance, especially with regard to the audio technology.
Automotive audio systems are quite different to home systems, mainly because of space constraints: in-vehicle speakers are different from those used in the home. While home systems have different speakers to cover the frequency range, in automotive applications tweeters and woofers are often combined into a single coaxial speaker.
At the heart of the audio system is the amplifier that defines the audio quality – needing a linear output to faithfully reproduce the sound content. However, in vehicle applications, the amplifier module is also required to detect system faults such as capacitor degradation that can cause a DC voltage offset that will destroy speakers.
As more electronics is added to vehicles and, especially as electric propulsion becomes popular in EV and HEV, the automotive environment is becoming very challenging from an EMI perspective making the delivery of a faithfully reproduced analog signal a challenge. Electric pumps for power steering, electric motors for windows and switching the power to electric motors are all potential sources of significant interference. Alongside this, start-stop systems can introduce significant spikes onto the power supply rails that feed the amplifier.
The Bill-of-Materials (BoM) is also an important consideration. Modern vehicles rarely have the space for a high component count, nor can manufacturers bear the cost of large complex BoMs.
Toshiba has produced a white paper that discusses the automotive design challenge in detail and proposes some solutions including the advanced TCB701FNG audio power amplifier IC. To download your free copy, please click here: