LM4910 - National Semiconductor

LM4910 Output Capacitor-less Stereo 35mW Headphone Amplifier

The LM4910 is an audio power amplifier primarily designed for headphone applications in portable device applications. It is capable of delivering 35mW 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 .

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 65dB (typ) n Power Output at VDD = 3.3V, RL = 32Ω, and THD ≤ 1% 35mW (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 el.