Efficient Class-D audio power amplifier for driving bridged-tied stereo speakers

The Texas Instruments TPA3140D2 is an efficient, Class-D audio power amplifier for driving bridged-tied stereo speakers at up to 10W/6ohm or 8ohm (per channel). Advanced EMI suppression technology with a spread-spectrum control and 1SPW modulation scheme enables the use of inexpensive ferrite bead filters at the outputs while meeting EMC requirements for system cost reduction. TPA3140D2 is not only fully protected against shorts and overload, the SpeakerGuard speaker protection circuitry includes an adjustable Automatic Gain Limit (AGL), an adjustable power limiter and a DC detection circuit for protection of the connected speakers. The AGL allows adjustment of the maximum output voltage without signal clipping for enhanced speaker protection and audio quality. The DC detect and Pin-to-Pin, Pin-to-Ground and Pin-to-Power Short Circuit protection circuit protect the speakers from output DC and pin shorts caused in production. The outputs are also fully protected against shorts to GND, PVCC, and output-to-output. The short-circuit protection and thermal protection includes an auto recovery feature. The TPA3140D2 can drive stereo speakers with as low as 4ohm impedance. The high efficiency of the TPA3140D2, 90% with 8ohm load, eliminates the need for an external heat sink, and TPA3140D2 will be able to output full power on a 2-layer PCB.