LM4947 Datasheet | National Semiconductor

Description The LM4947 is an audio subsystem capable of efficiently delivering 500m W (Class D operation) of continuous average power into a mono 8Ω bridged-tied load (BTL) with 1% THD+N, 37m W (Class AB operation) power 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 LM4947 has six input channels: one pair for a twochannel stereo signal, the second pair for a secondary twochannel stereo input, and the third pair for a differential single-channel mono input. Additionally, the two sets of stereo inputs may be configured as a single stereo differential input (differential left and differential right). The LM4947 features a 32-step digital volume control and eight distinct output modes. The digital volume control, 3D enhancement, and output modes are programmed through a two-wire I2C patible interface that allows flexibility in routing and mixing audio channels. The RF suppression circuitry in the LM4947 makes it wellsuited for GSM mobile phones and other portable applications in which strong RF signals generated by an antenna (and long output traces) may couple audibly into the amplifier. The LM4947 is designed for cellular phones, PDAs, and other portable handheld applications. It delivers high quality output power from a surface-mount package and requires only eight 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, 37m 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 Single Supply Operation Features n I2C Control Interface n I2C programmable National 3D Audio n I2C controlled 32 step digital volume control (-59.5d B to +18d B) n Three independent volume channels (Left, Right, Mono) n Eight distinct output modes n Small, 25- bump micro SMD...