LM4673 Datasheet | National Semiconductor

Description The LM4673 is a single supply, high efficiency, 2.65W, mono, Class D audio amplifier. A low noise, filterless PWM architecture eliminates the output filter, reducing external ponent count, board area consumption, system cost, and simplifying design. The LM4673 is designed to meet the demands of mobile phones and other portable munication 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 LM4673 has high efficiency with speaker loads pared to a typical Class AB amplifier. With a 3.6V supply driving an 8Ω speaker, the IC’s efficiency for a 100m W power level is 80%, reaching 88% at 400m W output power. The LM4673 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 LM4673 is externally configurable which allows independent gain control from multiple sources by summing the signals. Output short circuit and thermal overload protection prevent the device from damage during fault conditions. Key Specifications j Efficiency at 3.6V, 400m W into 8Ω speaker 88% (typ) j Efficiency at 3.6V, 100m W into 8Ω speaker 80% (typ) j Efficiency at 5V, 1W into 8Ω speaker j Quiescent current, 3.6V supply j Total shutdown power supply current j Single supply range j PSRR, f = 217Hz 86% (typ) 2.1m A (typ) 0.01µA (typ) 2.4V to 5.5V 78d B Features n n n n n n n n Mono Class D Operation No output filter required for inductive loads Externally configurable gain Very fast turn on time: 17µs (typ) Minimum external ponents "Click and pop" suppression circuitry Micro-power shutdown mode Available in space-saving 0.4mm pitch micro SMD and LLPTm (Future Product) packages Applications n Mobile phones n PDAs n Portable electronic devices Typical Application 201522J3 FIGURE 1. Typical Audio Amplifier Application Circuit Boomer ® is...