10-W Class-D amp integrates volume control

The MAX9768 mono 10-W Class-D speaker amplifier from Maxim Integrated Products features an integrated 64-step analog or digital programmable volume control and mute function. Analog volume control can be achieved using a DC voltage, potentiometer, filtered microcontroller PWM signal, or other analog signal; digital control is possible using the on-board I²C-compatible interface.

The MAX9768 operates from a 4.5 to 14-V single supply and can deliver up to 10 W into an 8-Ω speaker with a 14-V supply. The wide voltage range allows direct battery operation in portable applications, eliminating the need for a DC-DC converter between the battery and speaker amplifier.

A selectable spread-spectrum mode reduces EMI, allowing the device to pass EMC testing with ferrite bead filters and cable lengths up to 1 m. Other features include short-circuit and thermal-overload protection, and the ability to be synchronized to an external clock, allowing synchronization of multiple Class-D amplifiers.

Specifications include a PSRR of 77 dB, a THD+N of 0.08%, and an SNR of up to 97 dB. The MAX9768 is available in a 24-pin thin QFN-EP (4 x 4 x 0.8 mm) and is specified over the extended -40°C to +85°C temperature range.

Pricing: From $1.20 (1000-up, FOB USA).

Maxim Integrated Products, 1-800-998-8800, http://www.maxim-ic.com

Product literature:
MAX9768 data sheet (PDF)