The LM4873 is a dual bridge-connected audio power amplifier which, when connected to a 5V supply, will deliver 2.1W to a 4Ω load or 2.4W to a 3Ω load with less than 1.0% THD+N (see Notes below). In addition, the headphone input pin allows the amplifiers to operate in single-ended mode when driving stereo headphones. A MUX control pin allows selection between the two stereo sets of amplifier inputs. The MUX control can also be used to select two different closed-loop responses. Boomer audio power amplifiers were designed specifically to provide high quality output power from a surface mount package while requiring few external components. To simplify audio system design, the LM4873 combines dual bridge speaker amplifiers and stereo headphone amplifiers on one chip. The LM4873 features an externally controlled, low-power consumption shutdown mode, a stereo headphone amplifier mode, and thermal shutdown protection. It also utilizes circuitry to reduce “clicks and pops” during device turn-on. Note: An LM4873MTE-1, LM4873MTE, or LM4873LQ that has been properly mounted to a circuit board will deliver 2.1W into 4Ω. The other package options for the LM4873 will deliver 1.1W into 8Ω. See the sections for further information concerning the LM4873MTE-1, LM4873MTE, and the LM4873LQ. Note: An LM4873MTE-1, LM4873MTE, or LM4873LQ that has been properly mounted to a circuit board and forced-air cooled will deliver 2.4W into 3Ω.