LM4674 Datasheet | National Semiconductor

Description The LM4674 is a single supply, high efficiency, 2.5W/ channel, filterless switching audio amplifier. A low noise PWM architecture eliminates the output filter, reducing external ponent count, board area consumption, system cost, and simplifying design. The LM4674 is designed to meet the demands of mobile phones and other portable munication devices. Operating from a single 5V supply, the device is capable of delivering 2.5W/channel of continuous output power to a 4Ω load with less than 10% THD+N. Flexible power supply requirements allow operation from 2.4V to 5.5V. The LM4674 features high efficiency pared to conventional Class AB amplifiers. When driving and 8Ω speaker from a 3.6V supply, the device features 85% efficiency at PO = 500m W. Four gain options are pin selectable through the GAIN0 and GAIN1 pins. Output short circuit protection prevents the device from being damaged during fault conditions. Superior click and pop suppression eliminates audible transients on power-up/down and during shutdown. Independent left/right shutdown controls maximizes power savings in mixed mono/stereo applications. Key Specifications j Efficiency at 3.6V, 100m W into 8Ω j Efficiency at 3.6V, 500m W into 8Ω j Efficiency at 5V, 1W into 8Ω j Quiescent Power Supply Current 80% (typ) 85% (typ) 85% (typ) 4m A 2.5W (typ) 1.5W (typ) 0.1µA (typ) at 3.6V supply j Power Output at VDD = 5V, RL = 4Ω, THD ≤ 10% j Power Output at VDD = 5V, RL = 8Ω, THD ≤ 10% j Shutdown current Features n n n n n n n n n Output Short Circuit Protection Stereo Class D operation No output filter required Logic selectable gain Independent shutdown control Minimum external ponents Click and Pop suppression Micro-power shutdown Available in space-saving 2mm x 2mm x 0.6mm micro SMD package Applications n Mobile phones n PDAs n Laptops Boomer ® is a registered trademark of National Semiconductor Corporation. © 2005 National Semiconductor Corporation DS201674 .national. Typical...