540-mW, mono, 35-mW stereo, analog input Class-AB audio amplifier with I2C interface

The LM4946 is an audio power amplifier capable of delivering 540mW of continuous average power into a mono 8Ω bridged-tied

load (BTL) with 1% THD+N, 35mW per channel of continuous average power into stereo 32Ω single-ended (SE) loads with 1% THD+N,

or an output capacitor-less (OCL) configuration with identical specifications as the SE configuration, from a 3.3V power supply.

The LM4946 has three input channels: one pair for a two-channel stereo signal and the third for a differential single-channel

mono input. The LM4946 features a 32-step digital volume control and eight distinct output modes. The digital volume control,

3D enhancement, and output modes (mono/SE/OCL) are programmed through a two-wire I

2C or a three-wire SPI compatible interface that allows flexibility in routing and mixing audio channels.

The LM4946 is designed for cellular phone, PDA, and other portable handheld applications. It delivers high quality output

power from a surface-mount package and requires only seven external components in the OCL mode (two additional components

in SE mode).

Key Specifications

■

 THD+N at 1kHz, 540mW

 into 8Ω BTL (3.3V)

1.0% (typ)

■

 THD+N at 1kHz, 35mW

 into 32Ω SE (3.3V)

1.0% (typ)

■

 Single Supply Operation (VDD)

2.7 to 5.5V

■

I

2C/SPI Single Supply Operation

 LLP

2.2 to 5.5V

 micro SMD

1.7 to 5.5V