1997-12-23 , E/IC-847/510

Philips Semiconductors, the largest European semiconductor manufacturer, has introduced the world's first low-voltage, high-power, single-chip audio power amplifier to feature a fully integrated, push-button operated, digital volume control. Operating from a single 5- volt supply, the  TDA8551 delivers output powers as high as 1.4 W into an 8-ohm bridge- tied load, while exhibiting a remarkable degree of immunity to RF interference from sources such as cell-phone power amplifiers and car ignition systems. Up/down volume adjustment over an 80 dB range is achieved extremely simply by connecting two push- button switches or a rocker switch to the IC's volume control pin.

"The TDA8551's high output power, excellent EMC performance and single-pin volume control make it suitable for use in a vast range of applications, including hands-free telephones, pocket radios, headphone amplifiers, walkie-talkies, video games, answering machines and toys," commented product marketing manager Wladimir Punt. "In fact, any application that requires high-quality audio output at power levels below two watts," he added.

Although the TDA8551's unique push-button controlled single-pin digital volume control allows it to be used stand-alone in many instances, the volume control pin can just as easily be driven from a digital I/O port in microcontroller-based equipment. A second control input allows the TDA8551 to be muted or placed into a low-power standby mode, helping to save power consumption in battery powered systems.

Total harmonic distortion typically better than 0.15% at 0.5 W output, more than 50 dB rejection of supply rail ripple, and freedom from switch-on/switch-off noise, all contribute to excellent audio quality. Short-circuit proof outputs, plus built-in electrostatic discharge protection and thermal overload protection ensure excellent reliability. The TDA8551's excellent EMC performance means that no additional shielding is required, even when it is used inside RF equipment such as mobile phones.

Volume deliveries of the TDA8551, in either an 8-lead small-outline surface-mount or DIP package, are available now.

Philips Semiconductors, a division of Philips Electronics NV, headquartered in Eindhoven, The Netherlands, is the ninth largest semiconductor supplier in the world and the fourth largest supplier of discretes in the world. Philips Semiconductors' innovations in digital audio, video, and mobile technology position the company as a leader in the consumer, multimedia and wireless communications markets. Sales offices are located in all major markets around the world and are supported by systems labs.