Maxim Integrated Products introduces the MAX9791/MAX9792, said to be the industry's first Windows Vista-compliant, audio-subsystem ICs for notebook computers. These devices combine a stereo 2W (or mono 3W) Class D speaker amplifier, a stereo DirectDrive headphone amplifier, and a 120mA low-dropout (LDO) regulator in a single 4mm x 4mm chip. Consequently, the MAX9791/MAX9792 consume 36% less board space and 37% less power than competitive solutions, while enabling a richer audio experience. These audio-subsystem ICs are ideal for notebook PCs, docking stations, and other space-constrained applications.
Combining low power consumption with a highly efficient Class D speaker amplifier, the MAX9791/MAX9792 maximize battery life in all operating modes. Additionally, the high efficiencies delivered by the devices greatly ease the PCB thermal-design constraints that would be encountered utilizing Class AB amplifiers in confined spaces, such as notebook PCs. The ICs' low-EMI design reduces interference with the many radios found in today's notebooks, while their low RF susceptibility ensures robust operation in close proximity to wireless applications.
The headphone amplifiers employ Maxim's patented DirectDrive technology,* which produces a ground-referenced output from a single supply. This technology eliminates the need for bulky and expensive DC-blocking capacitors, while improving bass response and minimizing audio distortion. To further improve headphone performance, the MAX9791/MAX9792 incorporate ground-sense circuitry at the headphone jack. This feature significantly enhances crosstalk performance and rejects ground-loop-induced noise at the output jack.
The integrated 120mA LDO can be used to power the analog portion of the PC's audio codec, thereby improving system PSRR and reducing unwanted noises, buzzes, and clicks.
The MAX9791 features a stereo 2W speaker amplifier, and the MAX9792 has a mono 3W speaker amplifier. Both devices are fully specified over the -40 degrees Celsius to +85 degrees Celsius extended temperature range, and are available in a space-saving, 4mm x 4mm, 28-pin TQFN package. Prices start at $0.98 (1000-up, FOB USA).
Maxim Integrated Products, www.maxim-ic.com.
