Two automotive audio amplifiers from NXP Semiconductors support energy-saving start-stop systems. Both amplifiers use the company's mixed-signal technology. The TDF8530 is an efficient, quad-channel, Class-D audio amplifier supporting the 6V requirement for start-stop vehicles. The TDF8546 is a quad-channel, Class-AB amplifier available with a best efficiency mode operating as low as 6V. It reduces power dissipation by 17% compared to other high-efficiency solutions in its class, claims the company. Both amplifiers enable uninterrupted audio during sudden supply voltage drops down to 6V in hybrid electric vehicles, micro-hybrids, mild hybrids, and other cars using start-stop systems. The TDF8530 can be used for automotive head unit and sound system platforms in cars as well as in home entertainment systems. The Class-D amplifier is also designed to support new application areas such as car ambient sound systems, which can create engine sounds for electric vehicles. Maximum supply voltage is up to 24V delivering 72W/channel. In addition to start-up diagnostics, there are speaker protection, clip detection, and AC load tweeter detection. The four-channel has an output power of 4x25W and operates from six to 18V. There is no switch noise, due to switches in the signal path and its I2C bus diagnostics include start-up diagnostics, clip detection and pre-warning.
