Class D mono amplifier rated for 2.65 W into 4 Ω
The Texas Instruments LM4673SD/NOPB is a Class D mono audio amplifier from the Boomer® and PowerWise® series, delivering 2.65 W into a 4 Ω load from a single supply. Supply range spans 2.4 V to 5.5 V.
2.65 W — what that means for the BOM
That 2.65 W into 4 Ω is the maximum output power per channel at the rated load. For a portable speaker or soundbar channel, this delivers enough volume for a small enclosure without an external heatsink — the exposed pad on the 8-WSON (3x3) package pulls heat into the PCB copper. If your design needs more headroom, you step up to a higher-power Boomer® part; if efficiency at low volume matters more, the Class D topology already beats a linear Class AB on battery life.
Active production, no obsolescence concern
The LM4673SD/NOPB carries an Active lifecycle status from Texas Instruments. No last-time-buy or phase-out notice is on record. The part is fully ROHS3 compliant, so it meets current European and global material restrictions without exemption paperwork.
Package and mounting — 8-WSON with exposed pad
The 8-WSON exposed-pad package (3x3 mm) is a surface-mount footprint. The exposed pad must be soldered to a PCB thermal land and, ideally, connected to a ground plane for heat spreading. The part is available in Tape & Reel or Cut Tape — typical for pick-and-place assembly. No through-hole option exists.