Class D audio power stage with digital input pipeline
The TAS5711PHPR is a Class D audio amplifier IC from Texas Instruments that delivers 21W per channel into an 8Ω load across two channels, configurable as a 2-channel stereo, 2.1, or 4-channel quad output stage. The digital input path accepts I²S audio data and I²C control, integrating depop, mute, short-circuit protection, thermal shutdown, and volume control on-chip — reducing the external BOM to a few passive components and the output LC filter.
Output power and supply flexibility
Rated 21W x 2 at 8Ω, the output power is the headline selection parameter — it sets the maximum SPL into the connected speaker load before clipping. The 8V to 26V supply range covers common audio rails from a 12V automotive battery (nominal 13.8V) to a 24V industrial bus, so the same BOM can serve multiple product platforms with a supply-voltage change. The 2-channel (stereo), 2.1 (stereo plus subwoofer), or 4-channel (quad) output configuration is selected via I²C — the same PCB can support a 2.0 soundbar or a 2.1 system without a hardware change.
Thermal and package considerations for the layout
Housed in a 48-PowerTQFP (48-HTQFP 7x7mm) with an exposed thermal pad, the TAS5711PHPR's junction-to-ambient thermal resistance depends on the PCB copper area and via count under the pad. A 2-layer board with a solid thermal via array under the pad is the minimum for continuous 21W per channel; a 4-layer board with internal ground planes improves heat spreading and allows higher ambient operation within the 0°C to 85°C commercial temperature range. Surface-mount assembly with standard reflow profiles — the 48-HTQFP package is compatible with lead-free solder processes per the ROHS3 compliance status.
