LM4921 Datasheet | National Semiconductor

Description The LM4921 bines a 16-bit resolution stereo I S 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 munication 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 munication. With AVDD and DVDD = 3.0VDC and driving a 32Ω single-ended load to a 26m WRMS 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 ponents. 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. Key Specifications j PSRR at 217Hz, A/DVDD = 3V, (Fig. 1) j POUT at AVDD = 3.0V, 32Ω 52d B (typ) 13m W (typ) 26m W (typ) 2.6V to 5.0V 2.6V to 5.5V 1µA (typ) < 0.05% THD < 0.5% THD j Supply voltage range DVDD AVDD (Note 8) j Shutdown current Features n n n n n n n n n n 16-bit resolution stereo DAC I2S digital audio data serial interface SPI serial interface (control register) Volume Control (32 steps; 1.5 d B increments) Up to 50m W/channel stereo headphone amplifier Zero Crossing Detection for Silent Attenuation Steps 2.6VDC to 5.0VDC digital supply voltage range 2.6VDC to 5.5VDC analog supply voltage range (Note 8) Unity-gain stable headphone amplifiers Available in the 20-bump micro SMD package Applications n Mobile phones n PDAs n Portable electronic devices Boomer ® is a registered trademark of National Semiconductor Corporation. © 2004 National Semiconductor Corporation DS200486 .national....