Audio amplifiers include filtering for reduced smartphone interference

July 16, 2013 // By Christoph Hammerschmidt
NXP has announced enhancements to its family of Class-AB audio amplifiers, providing improved quiescent current reduction and decreased smart phone signal interference. The devices are targeting in particular automotive infotainment applications.

The integrated GSM input filtering is built in for increased EMC robustness. Building on NXP's expertise in Best Efficiency Mode audio applications, the TDFA8546A (4x 25Watt) and TDF8548A (4x 28Watt) are also the first Class-AB amplifiers to extend line driver detection to 1 kOhm load impedance.

As smartphone connectivity becomes increasingly central to automotive infotainment applications, the industry has to ensure that audio quality is not compromised by smartphone signal interference. Designed specifically for automotive applications, NXP’s Class-AB audio amplifiers provide increased GSM robustness, responding to OEMs’ demand for a cost-effective solution that improves sound quality.

The TDF8546, TDF8546A and TDF8548A amplifiers are quad-channel Class-AB amplifiers available with NXP’s  Best Efficiency Mode operating as low as 6V, reducing power dissipation by 17% compared to other high-efficiency solutions in its class. Both amplifiers enable a seamless audio experience during sudden supply voltage drops in hybrid electric vehicles and other cars using start-stop systems.

“In-car use of smart devices has become common over the past few years, but the potential interference they generate creates a major headache for audio OEMs aiming to provide excellent sound performance,” said Torsten Lehmann senior vice president and general manager car entertainment solutions at NXP Semiconductors. “These new amplifiers significantly reduce the effect that smart device signals can have on the speaker cable, while delivering superior sound performance.”

NXP; www.nxp.com/products/automotive/audio_amplifiers/class_ab_car_radio/