Active production — BOM-fit note
The MAX9762EUI: RoHS non-compliant — the part contains lead (Pb) above the exemption threshold, which matters for EU RoHS-required BOMs or end-equipment shipped into restricted markets.
3 W per channel into 3 Ω — what that means for the load
Rated 3 W x 2 into a 3 Ω load from a 5 V supply — this is the continuous sine-wave output before clipping, not a peak or burst rating. The 3 Ω figure is lower than the common 4 Ω or 8 Ω speaker impedance, so the amplifier delivers higher current per channel than a typical 8 Ω-rated part at the same supply voltage. Class AB topology means the output stage biases into conduction across the full waveform, avoiding the crossover distortion of Class B while running cooler than a pure Class A stage. The trade-off is quiescent current draw — budget the idle current into the 5 V rail when sizing the supply.
Package and thermal interface
28-TSSOP with exposed pad (EP) — the die-attach paddle on the underside of the package must be soldered to a PCB copper plane to pull heat out of the 3 W output stage. Without a thermal via array under the pad, the junction temperature rises above the 85 °C ambient limit at full output. The exposed pad is the main thermal path — the plastic TSSOP body alone cannot dissipate the 2–3 W of heat from both channels driven simultaneously. Layout should connect the EP to a ground plane with at least four thermal vias.