LM4921  Product Folder

The LM4921 combines a 16-bit resolution stereo I²S input digital-to-analog converter (DAC) with a stereo headphone audio power amplifier. It is primarily designed for demanding applications in mobile phones and other portable communication device applications. The LM4921 features an I²S serial interface for the digital audio information and a 16-bit SPI serial interface for internal register control and communication. With AV_DD and DV_DD = 3.0V_DC and driving a 32 single-ended load to a 26mW_RMS output level the distortion (THD+N) of the LM4921 will be less than 0.5%. The LM4921 also features a programmable 32-step digital volume control accessed through an SPI interface.

Boomer audio power amplifiers were designed specifically to provide high quality output power with a minimal amount of external components. It is, therefore, ideally suited for mobile phone and other low voltage applications where minimal power consumption is a primary requirement.

The LM4921 features a low-power consumption shutdown mode, and also has an internal thermal shutdown protection mechanism.

• 16-bit resolution stereo DAC
• I²S digital audio data serial interface
• SPI serial interface (control register)
• Volume Control (32 steps; 1.5 dB increments)
• Up to 50mW/channel stereo headphone amplifier
• Zero Crossing Detection for Silent Attenuation Steps
• 2.6V_DC to 5.0V_DC digital supply voltage range
• 2.6V_DC to 5.5V_DC analog supply voltage range (Note 8)
• Unity-gain stable headphone amplifiers
• Available in the 20-bump microSMD package

• Mobile phones
• PDAs
• Portable electronic devices