Package and integration story
The LM4916LD/NOPB is a Class AB audio amplifier from the Boomer® series, packaged in a 10-WSON (3x3 mm) with an exposed thermal pad. The 10-WFDFN footprint demands a solid thermal via array under the pad to keep the junction temperature within the -40°C to 85°C operating range when driving 85 mW into an 8 Ω mono load.
Output power and supply headroom
Rated output is 85 mW into 8 Ω from the mono bridge-tied load (BTL) channel, and 14 mW per channel into 16 Ω for the stereo headphone outputs. The supply voltage range of 0.9 V to 2.5 V means this part runs directly from a single Li-ion cell or two alkaline cells — the BTL topology doubles the voltage swing at the load, so the 85 mW figure is achievable at the lower end of the supply range only if the headroom above the dropout is maintained. Built-in depop, mute, shutdown, and thermal protection circuits prevent audible clicks on power-up and protect the output stage under fault conditions. The shutdown pin lets a microcontroller cut the quiescent current to near zero when the audio path is idle.