Mono audio subsystem with Class D speaker and Class G headphone drive
The Texas Instruments LM49153TMX/NOPB is a mono audio subsystem that combines a Class D speaker amplifier with a separate Class G headphone amplifier in a single 25-WFBGA package. It delivers 1.35 W into an 8 Ω speaker load and 25 mW per channel into 32 Ω headphones, making it a fit for portable devices that need both a loudspeaker and a headphone jack without a second amplifier IC. The I²C interface handles volume control, input multiplexer selection, and shutdown — all from the host processor. The input mux allows two differential sources to be routed to either the speaker or headphone path, which simplifies signal routing in a phone or tablet PCB. Supply range is 2.7 V to 5.5 V. Operating temperature range is -40°C to 85°C.
Output power and load budget
The speaker channel is rated for 1.35 W into 8 Ω — enough for a small enclosure speaker in a Bluetooth speaker, handheld radio, or portable instrument. The headphone outputs are rated at 25 mW into 32 Ω, which drives typical earbuds or headphones to a comfortable listening level without an external headphone amp. The depop feature suppresses the pop and click that otherwise occur when switching between speaker and headphone paths or during power-up. That matters for any product where the audio path transitions between modes — a phone switching from speakerphone to earpiece, for example.
Package and footprint
The 25-WFBGA measures 2.01 mm x 2.01 mm.