LM4935 Datasheet | National Semiconductor

LM4935 Audio Sub-System with Dual-Mode Stereo Headphone & Mono High Efficiency Loudspeaker Amplifiers and Multi-Purpose ADC October 2005 LM4935 Audio Sub-System with Dual-Mode Stereo Headphone & .. Mono High Efficiency Loudspeaker Amplifiers and Multi-Purpose ADC 1.0 General Description The LM4935 is an integrated audio subsystem that supports both analog and digital audio functions. The LM4935 includes a high quality stereo DAC, a mono ADC, a multipurpose SAR ADC, a stereo headphone amplifier, which supports output cap-less (OCL) or AC-coupled (SE)modes of operation, a mono earpiece amplifier and a mono high efficiency loudspeaker amplifier. It is designed for demanding applications in mobile phones and other portable devices. The LM4935 Features a bi-directional I2S serial interface for full range audio and an I2C or SPI patible interface for control. The stereo DAC path Features an SNR of 88 d B with an 18-bit 48 k Hz input. In SE mode the headphone amplifier delivers at least 33 m WRMS to a 32Ω single-ended stereo load with less than 1% distortion (THD+N) when A_VDD = 3.3V. The mono earpiece amplifier delivers at least 115 m WRMS to a 32Ω bridged-tied load with less than 1% distortion (THD+N) when A_VDD = 3.3V. The mono speaker amplifier delivers up to 600 m W into an 8Ω load with less than 1% distortion when LS_VDD = 3.3V and up to 1.3W when LS_VDD = 5.0V. The LM4935 also contains a general purpose SAR ADC for housekeeping duties such as battery and temperature monitoring. This can also be used for analog volume control of the output stages and can trigger interrupt events. The LM4935 employs advanced techniques to reduce power consumption, to reduce controller overhead to speed development time and to eliminate click and pop. Boomer audio power amplifiers were designed specifically to provide high quality output power with a minimal amount of external ponents. It is therefore ideally suited for mobile phone and other low voltage...