描述 Description

The LM4857 is an integrated audio sub-system designed for stereo cell phone applications. Operating on a 3.3V supply, it combines a stereo speaker amplifier delivering 495mW per channel into an 8? load, a stereo headphone amplifier delivering 33mW per channel into a 32? load, a mono earpiece amplifier delivering 43mW into a 32? load, and a line output for an external powered handsfree speaker. It integrates the audio amplifiers, volume control, mixer, power management control, and TI 3D enhancement all into a single package. In addition, the LM4857 routes and mixes the stereo and mono inputs into 16 distinct output modes. The LM4857 is controlled through an I2C compatible interface. Other features include an ultra-low current shutdown mode and thermal shutdown protection.

Boomer audio power amplifiers are designed specifically to provide high quality output power with a minimal amount of external components.

The LM4857 is available in a 30-bump DSBGA package and a 28–lead UQFN package.

特性 Features

? Stereo Speaker Amplifier
? Stereo Headphone Amplifier
? Mono Earpiece Amplifier
? Mono Line Output for External Handsfree Carkit
? Independent Left, Right, and Mono Volume Controls
? TI 3D Enhancement
? I2C Compatible Interface
? Ultra low Shutdown Current
? Click and Pop Suppression Circuit
? 16 distinct Output Modes
? Thermal Shutdown Protection
? Available in DSBGA and UQFN packages
Key Specifications
? POUT, Stereo Loudspeakers, 4Ω, 5V, 1% THD+N (LM4857SP) 1.6W (typ)
? POUT, Stereo Loudspeakers, 8Ω, 5V, 1% THD+N 1.2W (typ)
? POUT, Stereo Headphones, 32Ω, 5V, 1% THD+N 75mW (typ)
? POUT, Mono Earpiece, 32Ω, 5V, 1% THD+N 100mW (typ)
? POUT, Stereo Loudspeakers, 8Ω, 3.3V, 1% THD+N 495mW (typ)
? POUT, Stereo Headphones, 32Ω, 3.3V, 1% THD+N 33mW (typ)
? POUT, Mono Earpiece, 32Ω, 3.3V, 1% THD+N 43mW (typ)
? Shutdown Current 0.06μA (typ)