Class D amplifier for compact stereo designs
The TPA2008D2PWP is a 3W per channel Class D stereo amplifier in a 24-HTSSOP package with an exposed thermal pad. Class D topology means the output stage switches at high frequency, so efficiency stays above 80% even at moderate output levels — the part dissipates less heat than a linear amp delivering the same power, which is the difference between needing a heatsink and running bare on a two-layer board in a sealed enclosure. Rated 3W x 2 into 3 Ohm loads from a 4.5V to 5.5V supply, this part drives small speakers directly. The 4.5V floor means it still delivers rated power when a 5V rail droops under load or a lithium battery nears its discharge cutoff — a common headache in portable designs that a linear amp with higher dropout voltage would struggle with.
Industrial temperature grade and supply flexibility
The single 5V supply rail simplifies the power tree — no split rails, no charge pump, just a clean 5V bus from a USB port or a simple buck converter. The exposed pad on the 24-HTSSOP package is the primary thermal path. A PCB layout that stitches the pad to a copper pour with vias under the package keeps junction temperature within limits at full output into 3 Ohm loads. The datasheet's thermal impedance curves assume a 1-square-inch copper area on the bottom layer — a smaller pour raises the junction temperature by roughly 20°C/W.
Built-in protection reduces external BOM
Short-circuit and thermal protection are integrated, so a faulted speaker wire or a stalled cooling fan does not take out the amplifier. The shutdown pin lets a microcontroller or a system supervisor cut power to the output stage, dropping quiescent current to near zero during idle periods. Differential inputs reject common-mode noise picked up on long input traces — useful when the audio source is on a separate board connected by a ribbon cable inside a noisy enclosure. The depop circuit suppresses the turn-on thump that otherwise sends a DC transient into the speakers.
Supplied in tube packaging, 50 pieces per tube. The 24-HTSSOP footprint is shared with several other TI audio amplifiers in the same family, so a single PCB layout can support multiple BOM variants by populating a different amplifier IC.