LM4845 Datasheet | National Semiconductor

Description The LM4845 is an audio power amplifier capable of delivering 500m W of continuous average power into a mono 8Ω bridged-tied load (BTL) with 1% THD+N, 25m W 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 specification as the SE configuration, from a 3.3V power supply. The LM4845 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 I2C or a three-wire SPI patible interface that allows flexibility in routing and mixing audio channels. The LM4845 has three input channels: one pair for a two-channel stereo signal and the third for a single-channel mono input. The LM4845 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 ponents in the OCL mode (two additional ponents in SE mode). Key Specifications j THD+N at 1k Hz, 500m W into 8Ω BTL (3.3V) j THD+N at 1k Hz, 25m W 1.0% (typ) 1.0% (typ) 2.7 to 5.5V 2.2 to 5.5V into 32Ω SE (3.3V) j Single Supply Operation (VDD) j I2C/SPI Single Supply Operation Features n I2C/SPI Control Interface n I2C/SPI programmable National 3D Audio n I2C/SPI controlled 32 step digital volume control (-54d B to +18d B) n Three independent volume channels (Left, Right, Mono) n Eight distinct output modes n micro SMD surface mount packaging n “Click and Pop” suppression circuitry n Thermal shutdown protection n Low shutdown current (0.1u A, typ) Applications n Moblie Phones n PDAs Boomer ® is a registered trademark of National Semiconductor Corporation. © 2005 National Semiconductor Corporation DS201059 .national. Typical Application .. FIGURE 1. Typical Audio Amplifier Application Circuit-Output Capacitor-less .national. Typical...