描述 Description

The LM49200 is a fully integrated audio subsystem with a stereo power amplifier capable of delivering 500mW of continuous average power per channel into 8? with 1% THD+N using a 3.3V supply. The LM49200 includes a separate stereo headphone amplifier that can deliver 35mW per channel into 32?. The LM49200 has three input channels. A pair of single-ended inputs and a fully differential input channel. The LM49200 features a 32-step digital volume control on the input stage and an 8-step digital volume control on the headphone output stage. The digital volume control and output modes are programmed through a two-wire I2C compatible interface that allows flexibility in routing and mixing audio channels. The LM49200 is designed for cellular phone, PDA, and other portable handheld applications. The high level of integration minimizes external components. The True Ground headphone amplifier eliminates the physically large DC blocking output capacitors reducing required board space and reducing cost.

特性 Features

? Differential Mono Input and Stereo Single-Ended Input
? 32-Step Digital Volume Control (-80 to +18dB)
? Three Independent Volume Channels (Left, Right, Mono)
? Separate Headphone Volume Control
? Flexible Output for Speaker and Headphone Output
? True Ground Headphone Amplifier Eliminates Large DC Blocking Capacitors Reducing PCB Space and Cost
? Receiver Pass-Through Capability
? Soft Enable Function
? RF Immunity Topology
? “Click and Pop” Suppression Circuitry
? Thermal Shutdown Protection
? Micro-Power Shutdown
? I2C Control Interface
? Available in Space-Saving DSBGA Package
Key Specifications
? Supply Voltage (VDD): 2.7V ≤ VDD ≤ 5.5V
? I2C Supply Voltage: 1.7V ≤ I2CVDD ≤ 5.5V
? Output power at VDD = 5V, 1% THD+N
? RL = 8Ω speaker: 1.25W (typ)
? RL = 32Ω headphone: 38mW (typ)

? Output power at VDD = 3.3V, 1% THD+N
? RL = 8Ω speaker: 520W (typ)
? RL = 32Ω headphone: 38mW (typ)

? PSRR:
? VDD = 3.3V, 217Hz ripple, Mono In: 95dB (typ)

? Shutdown power supply current 0.02μA (typ)