Technical Paper
New Approaches for Low Voltage Audio System and Circuit Design
2012-04-16
2012-01-0037
New vehicle systems that stop and restart the engine to avoid prolonged idling place new requirements on audio systems. In particular, there is a need for the audio system to continue to operate during the engine start sequence. In the past this was not an issue, as audio systems could be turned off during the engine start sequence. Among the ramifications for this “operate while starting” requirement is that the audio system must operate at a lower voltage, say 6 volts, instead of 10 volts. Audio system operation in this context means continuing to play music without interruption or spurious noises. The main focus of this presentation is on audio circuits, both line-level and speaker level. In the past, line level outputs could be fed by linear regulated power supplies that developed 8 to 10 volts. The signal levels sent from one module to another could thus be in the 3 volt RMS range.
