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LM48413 Ultra Low EMI, Filterless, 1.2W Stereo Class D Audio Power Amplifier with E2S and National 3D Enhancement
www.DataSheet4U.com
January 9, 2009
LM48413 Ultra Low EMI, Filterless, 1.2W Stereo Class D Audio Power Amplifier with E2S and National 3D Enhancement
General Description
The LM48413 is a single supply, high efficiency, 1.2W/channel, filterless switching audio amplifier. The LM48413 features National’s Enhanced Emissions Suppression (E2S) system - a unique patented ultra low EMI, spread spectrum, PWM architecture. It significantly reduces RF emission while preserving audio quality and efficiency. The E2S system improves battery life, reduces external component count, board area consumption, system cost and product design cycle time. The LM48413TL is available in a micro-SMD package, further saving space. The LM48413 is designed to meet the demands of mobile phones and other portable communication devices. Operating from a single 5V supply, the device is capable of delivering 1.2W/channel of continuous output power to a 8Ω load with less than 1% THD+N. Flexible power supply requirements allow operation from 2.4V to 5.5V. The wide band spread spectrum architecture of the LM48413 reduces EMI-radiated emissions due to the modulator frequency. The LM48413 features high efficiency compared with conventional Class AB amplifiers. The E2S system includes an advanced, patent-pending edge rate control (ERC) architecture that further reduce emissions by minimizing the high frequency components of the device output, while maintaining its high quality audio reproduction and high efficiency (η = 85% at VDD = 3.6V, PO = 500mW). The LM48413 also includes National’s 3D audio enhancement that improves stereo sound quality. In devices where the left and right speakers are in close proximity, 3D enhancement affects channel specialization, widening the perceived soundstage. 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. Shutdown control also provided to maximizes power savings.
Key Specifications
■ Quiescent Power Supply Current
at 3.6V supply 4mA (typ) 1.2W (typ) 0.03μA (typ) 80% (typ) 85% (typ) 86% (typ)
■ Power Output at VDD = 5V, RL = 8Ω, THD ≤ 1% ■ Shutdown current ■ Efficiency at 3.6V, 100mW into 8Ω ■ Efficiency at 3.6V, 500mW into 8Ω ■ Efficiency at 5V, 1W into 8Ω
Features
■ E2S system reduces EMI preserving audio quality and ■ ■ ■ ■ ■ ■ ■ ■
efficiency Output Short Circuit Protection Stereo Class D operation No output filter required National 3D Enhancement Minimum external components Click and Pop suppression Micro-power shutdown Available in space-saving approximately 2mm x 2.2mm micro SMD package
Applications
■ Mobile phones ■ PDAs ■ Laptops
EMI Plot Using 6 inch Speaker Cables
EMI Radiation vs Frequency VDD = 3V, RL = 15μH + 8Ω + 15μH
30063536
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