LM4867 Datasheet | National Semiconductor

LM4867 Output-Transient-Free Dual 2.1W Audio Amplifier Plus No Coupling Capacitor Stereo Headphone Function February 2001 LM4867 Output-Transient-Free Dual 2.1W Audio Amplifier Plus No Coupling Capacitor Stereo Headphone Function General Description The LM4867 is a dual bridge-connected audio power amplifier which, when connected to a 5V supply, will deliver 2.1W to a 4Ω load (Note 1) or 2.4W to a 3Ω load (Note 2) with less than 1.0% THD+N. The LM4867 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. 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 ponents. To simplify audio system design, the LM4867 bines dual bridge speaker amplifiers and stereo headphone amplifiers in one package. The LM4867 Features an externally controlled power-saving micropower shutdown mode, a stereo headphone amplifier mode, and thermal shutdown protection. Note 1: An LM4867LQ or LM4867MTE that has been properly mounted to a circuit board will deliver 2.1W into 4Ω. The Mux control can also be used to select two different closed-loop responses. LM4867MT will deliver 1.1W into 8Ω. See the Application Information sections for further information concerning the LM4867LQ and the LM4867MT. Note 2: An LM4867LQ or LM4867MTE that has been properly mounted to a circuit board and forced-air cooled will deliver 2.4W into 3Ω. Key Specifications n PO at 1% THD+N n LM4867LQ, 3Ω load 2.4W (typ) n LM4867LQ, 4Ω load 2.1W...