LM4904 Datasheet | National Semiconductor

Description The LM4904 is an audio power amplifier primarily designed for demanding applications in mobile phones and other portable munication device applications. It is capable of delivering 1 watt of continuous average power to an 8Ω BTL load with less than 1% distortion (THD+N) from a 5VDC power supply. Boomer audio power amplifiers were designed specifically to provide high quality output power with a minimal amount of external ponents. The LM4904 does not require output coupling capacitors or bootstrap capacitors, and therefore is ideally suited for mobile phone and other low voltage applications where minimal power consumption is a primary requirement. The LM4904 features a low-power consumption shutdown mode, which is achieved by driving the shutdown pin with logic high. Additionally, the LM4904 features an internal thermal shutdown protection mechanism. The LM4904 contains advanced pop & click circuitry which eliminates noise which would otherwise occur during turn-on and turn-off transitions. The LM4904 is unity-gain stable and can be configured by external gain-setting resistors. Key Specifications j Improved PSRR at 217Hz & 1KHz j Power Output at 5.0V, 1% THD, 8Ω j Power Output at 3.0V, 1% THD, 4Ω j Power Output at 3.0V, 1% THD, 8Ω j Shutdown Current 62d B 1.07W (typ) 525m W (typ) 390m W (typ) 0.1µA (typ) Features n n n n n n n n Available in space-saving micro SMD package Ultra low current shutdown mode BTL output can drive capacitive loads Improved pop & click circuitry eliminates noise during turn-on and turn-off transitions 2.0 - 5.5V operation No output coupling capacitors, snubber networks or bootstrap capacitors required Unity-gain stable External gain configuration capability Applications n Mobile Phones n PDAs n Portable electronic devices Typical Application 200437B6 FIGURE 1. Typical Audio Amplifier Application Circuit Boomer ® is a registered trademark of National Semiconductor Corporation. © 2004 National Semiconductor Corporation DS2...