Output-Transient-Free Dual 2.1W Audio Amplifier Plus No Coupling Capacitor Stereo Headphone Function

The LM4868 is a dual bridge-connected Audio Power Amplifier which, when connected to a 5V supply, will deliver 2.1W to a 4 load or 2.4W to a 3 load with less than 1.0% THD+N. The LM4868 uses advanced, latest generation circuitry to eliminate all traces of clicks and pops when the supply voltage is first applied. The Amplifier has a headphone-amplifier-select input pin. It is used to Switch the Amplifiers from bridge to single-ended mode for driving Headphones A new circuit topology eliminates Headphone output coupling capacitors (patent pending). A MUX control pin allows selection between the two sets of stereo input signals. The MUX control CAN also be used to select between two different customer-specified closed-loop responses.
Boomer Audio Power Amplifiers are designed specifically to provide high quality output power from a surface mount package and require few external components. To simplify Audio system design, the LM4868 combines dual bridge speaker Amplifiers and stereo Headphone Amplifiers in one package.
The LM4868 features an externally controlled power-saving micropower shutdown mode, a stereo Headphone Amplifier mode, and thermal shutdown protection.
By National Semiconductor Corporation