LM4906

LM4906 1W, Bypass-Capacitor-less Audio Amplifier with Internal Selectable Gain May 2003 LM4906 1W, Bypass-Capacitor-less Audio Amplifier with Internal Selectable Gain General Description The LM4906 is an audio power amplifier primarily designed for demanding applications in mobile phones and other portable communication device applications. It is capable of delivering 1W of continuous average power to an 8Ω BTL load with less than 1% distortion (THD+N) from a +5V power supply. The LM4906 is the first National Semiconductor Boomer Power Amplifier that does not require an external PSRR bypass capacitor. The LM4906 also has an internal selectable gain of either 6dB or 12dB. In addition, no output coupling capacitors or bootstrap capacitors are required which makes the LM4906 ideally suited for cell phone and other low voltage portable applications. The LM4906 contains advanced pop and click circuitry that eliminates noise, which would otherwise occur during turn-on and turn-off transitions. Boomer audio power amplifiers were designed specifically to provide high quality output power with a minimal amount of external components. The LM4906 features a low -power consumption shutdown mode (the part is enabled by pulling the SD pin high). Additionally, the LM4906 features an internal thermal shutdown protection mechanism. Key Specifications j Improved PSRR at 217Hz for +3V j Power Output at +5V, THD+N = 1%, 8Ω j Total shutdown power supply current 71dB 1.0W (typ) 0.1µA (typ) j ...