LM4671

LM4671 Filterless High Efficiency 2.5W Switching Audio Amplifier www.DataSheet4U.com March 3, 2008 LM4671  Filterless High Efficiency 2.5W Switching Audio Amplifier General Description The LM4671 is a single supply, high efficiency 2.5W switching audio amplifier. A low noise, filterless PWM architecture eliminates the output filter, reducing external component count, board area consumption, system cost, and simplifying design. The LM4671 is designed to meet the demands of mobile phones and other portable communication devices. Operating on a single 5V supply, it is capable of driving a 4Ω speaker load at a continuous average output of 2.1W with less than 1% THD+N. Its flexible power supply requirements allow operation from 2.4V to 5.5V. The LM4671 has high efficiency with speaker loads compared to a typical Class AB amplifier. With a 3V supply driving an 8Ω speaker, the IC's efficiency for a 100mW power level is 80%, reaching 88% at 400mW output power. The LM4671 features a low-power consumption shutdown mode. Shutdown may be enabled by driving the Shutdown pin to a logic low (GND). The gain of the LM4671 is externally configurable which allows independent gain control from multiple sources by summing the signals. Key Specifications ■ Efficiency @ 3.6V, 100mW into   8Ω speaker 80% (typ) 88% (typ) 86% (typ) 2.8mA (typ) 0.01µA (typ) 2.4V to 5.5V ■ Efficiency @ 3.6V, 400mW into    8Ω speaker speaker ■ Efficiency @ 5V, 1W into 8Ω ■ Quiescent current, 3.6V supply ■ Total shu...