National Semi expands hi-fi audio amplifier range

National Semiconductor has added to its LME hi-fi audio amplifier family with a pair of 200V mono audio power amplifier input stages designed to deliver low distortion.

The LME49811 and LME49830 offer scalable output power based on supply voltage and output device count. With these devices, designers can use the same base circuit design to create multiple power-level solutions up to 1 kW amplifiers, just by scaling the output stage devices to accommodate for more power dissipation and current drive.

When implemented in a complete power amplifier design, the LME49811's total harmonic distortion plus noise (THD+N) is a remarkably low 0.00035 per cent, while the LME49830's THD+N is 0.0006 per cent.

The LME49811 drives Darlington or bipolar power transistors in an amplifier's output stage. It is a mono version of the LM4702 stereo driver.

It is capable of driving an output stage to deliver in excess of 500W single-ended into an 8ohm load. 

The LME49830 can drive an output stage in excess of 500W single-ended into an 8ohm load. The device's 60mA output current can increase design flexibility when selecting output stage configurations. The LME49830 provides slew rates of 40V/[micro]s, PSRR of 115dB, output voltage noise of 41[micro]V and an operating voltage range of +/-20V to +/-100V.