Class D efficiency and the 2W stereo output
The TPA2000D2PWP is a Class D stereo amplifier delivering 2W per channel into a 3 ohm load from a 4.5V to 5.5V supply. Class D topology means the output stage switches at high frequency, so the device runs cooler than a linear amplifier at the same output power — a real advantage in a portable speaker or a slim TV where the enclosure has no fan and the PCB copper is the only heatsink.
What the supply and temperature range mean for the BOM
The 4.5V to 5.5V supply window is tight — it matches a single-cell Li-ion battery (3.7V nominal boosted to 5V) or a USB 5V rail. If the rail droops below 4.5V under full load, the amplifier will clip or shut down. Features like depop (pop-free turn-on/off), differential inputs (rejects ground noise on the input signal), short-circuit and thermal protection, and a shutdown pin are built in. The depop circuit eliminates the audible thump when the amplifier powers up or down — a common complaint in consumer audio that this part avoids without external circuitry.
Package and board-fit: the exposed-pad requirement
The 24-HTSSOP package has an exposed pad on the underside that must be soldered to a copper land on the PCB. That land should connect to a ground plane with thermal vias to pull heat away from the die. Without this thermal path, the device will hit its thermal shutdown threshold at lower output power — especially when driving 3 ohm loads at high volume. The package is surface-mount, supplied in a tube. The 0.65mm pin pitch is standard for TSSOP-24 and is routable on a two-layer board if the designer keeps the traces short and wide for the output current.