High output from power-efficient audio amplifier IC

The LM4950 power amplifier IC from National Semiconductor provides a compact solution for audio applications up to 7.5W, and enables easy design completion with minimal external passive components.

Benefits include low distortion, low quiescent current, high stability and a low-power shutdown mode that reduces current draw to 40µA. When operated from a 12V power supply the LM4950 will drive 3.1W per channel into a 4Ω load at THD+N of less than 1%, or 7.5W of mono audio power into an 8Ω Bridge-Tied Load (BTL) configuration at less than 10% THD+N.

Optimised to produce a high-quality output without requiring specialist audio design skills, the LM4950 requires no bootstrap capacitors or snubber circuits. Pop-and-click suppression is also implemented on-chip, saving a bulky external relay. Essential protection mechanisms are provided, including thermal shutdown and short-circuit protection.

The design can be completed with the addition of external gain-setting resistors, plus coupling and bypass capacitors.

 

FEATURES Supply voltage range: 9.6V to 16V 16mA quiescent current Unity-gain stable 9-pin TO-220 or TO-263 package options External Shutdown pin

APPLICATIONS Closed-circuit TV Security monitors Audio guides Gaming machines

 

 

National Semiconductor/LM4950