LM4910 Datasheet | National Semiconductor

LM4910 Output Capacitor-less Stereo 35m W Headphone Amplifier February 2003 LM4910 Output Capacitor-less Stereo 35m W Headphone Amplifier General Description The LM4910 is an audio power amplifier primarily designed for headphone applications in portable device applications. It is capable of delivering 35m W of continuous average power to a 32Ω load with less than 1% distortion (THD+N) from a 3.3VDC power supply. The LM4910 utilizes a new circuit topology that eliminates output coupling capacitors and half-supply bypass capacitors (patent pending). The LM4910 contains advanced pop & click circuitry which eliminates noises caused by transients that would otherwise occur during turn-on and turn-off. Boomer audio power amplifiers were designed specifically to provide high quality output power with a minimal amount of external ponents. Since the LM4910 does not require any output coupling capacitors, half-supply bypass capacitors, or bootstrap capacitors, it is ideally suited for low-power portable applications where minimal space and power consumption are primary requirements. The LM4910 Features a low-power consumption shutdown mode, activated by driving the shutdown pin with logic low. Additionally, the LM4910 Features an internal thermal shutdown protection mechanism. The LM4910 is also unity-gain stable and can be configured by external gain-setting resistors. Key Specifications n PSRR at f = 217Hz 65d B (typ) n Power Output at VDD = 3.3V, RL = 32Ω, and THD ≤ 1% 35m W (typ) n Shutdown Current 0.1µA (typ) Features n Eliminates headphone amplifier output coupling capacitors (patent pending) n Eliminates half-supply bypass capacitor (patent pending) n Advanced pop & click circuitry eliminates noises during turn-on and turn-off n Ultra-low current shutdown mode n Unity-gain stable n 2.2V - 5.5V operation n Available in space-saving MSOP, LLP, and SOIC packages Applications n n n n Mobile Phones PDAs Portable eletronics devices Portable MP3 players Typical...