Class-D audio power amps cuts PCB size by half

Texas Instruments Inc. has introduced the TPA203xD1 family of fixed gain Class-D audio power amplifiers for portable applications that require higher performance within limited board space, such as cellphones, portable media players handheld gaming devices and portable mini-speakers.

The new amplifiers complement TI's TPA2010D1 variable gain Class-D amplifier. By integrating the external input resistors and very closely matching them, the new amps enable designers to reduce overall board size by approximately 50 percent, the company said. The devices also improve power supply rejection ratio (PSRR) by 20dB and common-mode rejection ratio (CMRR) by 12dB, compared to designing with 5 percent matched external resistors that are commonly used in portable consumer electronics to reduce cost.

TI said the new amplifier family delivers 88 percent efficiency and drives 2.75W from a 5V power supply into 4 ohms with a low 27μVrms A-weighted noise floor. The amplifiers come in a compact and Pb-free 1.5-by-1.5mm WCSP that eliminates bond wires and lead frames required for QFN and BGA packaging, according to TI, and they consume only 2.5-by-1.7mm PCB area.

"As more and more portable audio customers are making the move to Class-D amplifiers, TI's expertise and innovative products are proving to be a tremendous asset in this competitive market," said Nicholas Holland, high performance analog marketing manager at Texas Instruments. "The TPA203xD1 amplifiers provide more than 2.5x power efficiency compared to Class-AB for customers who want to extend battery life and provide a better audio experience while using less board space."

The TPA2032D1, TPA2033D1 and TPA2034D1 offer fixed gain amplification of 2V/V (6dB), 3V/V (9.5dB) and 4V/V (12dB), respectively. Already available in production volumes, TPA203xD1 devices cost 60 cents each in 1,000 unit quantities. An evaluation module is available to support all three devices.