LM4681 Datasheet | National Semiconductor

Description The LM4681 is a fully integrated single supply, CLASS D audio power amplifier solution. The LM4681 utilizes a proprietary balanced pulse-width modulation technique that lowers output noise and THD and improves PSRR when pared to conventional pulse width modulators. The LM4681 also features a stereo headphone amplifier that delivers 80m W into a 32Ω headset with less than 0.5% THD. The LM4681’s I2C/SPI (selectable) volume control has a +30d B to - 48d B range when speakers are driven and a range of +13d B to - 65d B when headphones are connected. All amplifiers are protected by thermal shutdown. Additionally, the high efficiency power amplifiers have output current limit. With a 8Ω load, the IC’s efficiency for a 6W power level is 85%. The IC features click and pop reduction circuitry that minimizes audible popping during device turn-on and turnoff. The LM4681 is available in a 48-lead LLP package, ideal for portable and desktop puter applications. Key Specifications n n n n n n PO at THD+N =10%, AV = 30d B, VDD = 14V 10W (typ) THD+N at 1k Hz at 1W into 8Ω (Power Amp) 0.43% (typ) Efficiency at 7W into 8Ω 85% (min) Total quiescent power supply current 50m A (typ) THD+N 1k Hz, 20m W, 32Ω (Headphone) 0.02% (typ) Single supply range 9.0V to 15.5V Features n n n n n n Pulse-width modulator. I2C/SPI (selectable) volume control Stereo headphone amplifier. “Click and pop” suppression circuitry. Micropower shutdown mode. 48 lead LLP package (No heatsink required). Applications n Flat Panel Displays n Televisions n Multimedia Monitors Block Diagram Block Diagram for LM4681 BOOMER™ is a trademark of National Semiconductor Corporation. © 2006 National Semiconductor Corporation DS201189 .national. Connection Diagram LLP Package Top View Order Number LM4681SQ See NS Package Number SQA048AA (LLP Package) .national. Figure 1. Typical Application .national. Absolute Maximum Ratings (Note 2) If Military/Aerospac...