Class D amp with flexible output configuration
The Texas Instruments TPA3121D2PWPR is a Class D audio amplifier IC that delivers 30W into an 8Ω load in mono mode, or 15W per channel into 4Ω in stereo mode. It runs from a 10V to 26V supply and is specified over the -40°C to 85°C industrial temperature range. The 24-HTSSOP package with exposed pad needs a thermal land on the PCB for heat sinking — plan for that in the layout. On-chip features include depop, mute, short-circuit and thermal protection, and shutdown control.
Output power and load matching
The 30W mono rating into 8Ω suits a single-speaker soundbar or subwoofer channel; the 15W stereo into 4Ω drives a pair of bookshelf speakers in a multi-media system. The supply voltage directly affects output swing — a 26V rail gives the full 30W, while a 12V rail will deliver proportionally less. Check your speaker impedance and supply headroom before locking the BOM.
Supply range and thermal design
The 10V to 26V supply range lets you run from a standard 12V automotive battery or a 24V industrial rail without a separate regulator. The exposed pad on the 24-HTSSOP must be soldered to a copper plane on the PCB — the datasheet's thermal land pattern is the starting point. Without that thermal path, the thermal protection will trip at lower output levels.