Part # LM4670 datasheet

Part Manufacturer: National Semiconductor

National Semiconductor

Part Description: LM4670 Boomer ® Audio Power Amplifier Series Filterless High Efficiency 3W Switching Audio Amplifier


Part Details:

LM4670 July 2006 Filterless LM4670Filterless High Efficiency 3W Switching Audio AmplifierGeneral Description Key Specifications The LM4670 is a fully integrated single-supply high efficiency j Efficiency at 3.6V, 100mW into 8 speaker 77% (typ) High switching audio amplifier. It features an innovative modulatorthat eliminates the LC output filter used with typical switching j Efficiency at 3.6V, 600mW into 8 speaker 88% (typ) amplifiers. Eliminating the output filter reduces external com- j Efficiency at 5V, 1W into 8 speaker 87% (typ) ponent count, simplifies circuit design, and reduces board Efficiency j Quiescent current, 3.6V supply 4.8mA (typ) area. The LM4670 processes analog inputs with a delta- j Total shutdown power supply current 0.01µA (typ) sigma modulation technique that lowers output noise andTHD when compared to conventional pulse width modula- j Single supply range 2.4V to 5.5V tors. The LM4670 is designed to meet the demands of mobile Features phones and other portable communication devices. Operat-ing on a single 5V supply, it is capable of driving a 4 n No output filter required for inductive loads 3W speaker load at a continuous average output of 2.3W with n Externally configurable gain less than 1% THD+N. Its flexible power supply requirements n Very fast turn on time: 1.35ms (typ) allow operation from 2.4V to 5.5V. Switching n Minimum external components The LM4670 has high efficiency with speaker loads com- n "Click and pop" suppression circuitry pared to a typical Class AB amplifier. With a 3.6V supply n Micro-power shutdown mode driving an 8 speaker, the IC s efficiency for a 100mW n Short circuit protection power level is 77%, reaching 88% at 600mW output power. n Available in space-saving microSMD and LLP packages The LM4670 features a low-power consumption shutdownmode. Shutdown may be enabled by driving the Shutdown Applications Audio pin to a logic low (GND). n Mobile phones The gain of the LM4670 is externally configurable which n PDAs allows independent gain control from multiple sources bysumming the signals. n Portable electronic devices Amplifier Typical Application


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LM4670.pdf Datasheet