Dual audio op amp practically 'eliminates' distortion

National Semiconductor Corp. has announced a dual, high-fidelity audio op amp claimed to practically eliminate distortion, with a THD+N of 0.00003 percent. The LM4562 features very low distortion, low noise, high speed, wide operating voltage and high output drive, making it suitable for professional and high-end audio applications such as audio/visual (A/V) receivers, preamplifiers and mixers, as well as a range of 34V medical imaging and industrial applications.

Unique design
The new device combines a high-speed 6MHz unity-gain bandwidth op amp with a new proprietary stereo audio power amplifier that offers all key specifications needed for superior audio performance and signal conditioning, the company said. The op amp features low-input noise density of 2.7nV/√Hz at 217Hz, a 1/f noise corner of 60Hz and 600-ohm output drive.

To ensure that the most challenging high loads are driven without any noise compromise, the company said this op amp has a slew rate of 20V/?s and a 56MHz gain bandwidth. The device is available in 8-lead SOIC, dual in-line (DIP) and metal can packages. Single and quad versions of the op amp will be available in early 2007.

The LM4562 is unity-gain stable over a wide supply range of ±2.5V to 17V and has an output current capability of 45mA. Over this supply range, the device's input circuitry maintains common-mode and PSRR of more than 108db and a typical low input bias current of 10nA. The op amp offers a full audio dynamic range maximized with an output stage. This output stage can swing to within 1V of either power supply voltage when driving 2-kiloohm loads or to within 1.5V when driving 600-ohm loads.

Protection features
The op amp retains its performance levels while driving capacitive loads as high as 100pF. It also features thermal shutdown and output short-circuit protection.

Available now, the LM4562's standard SOIC package is priced at $2.35 each and the DIP package is priced at $2.65 each in 1,000-unit quantities. The metal can package is priced at $9.95 each in 100-unit quantities. Lead-free package options that are compliant with the RoHS directive are also available.