National Semiconductor expands high-fidelity op amp line
Santa Clara, Calif. — National Semiconductor has expanded its high-fidelity operational amplifier family with the introduction of 5-V rail-to-rail input and output (RRIO) and 36-V current feedback operational amplifiers (op amps).

The LME49721 RRIO op amp provides the high-fidelity performance and signal conditioning required by high-end portable devices and applications where supply rails are limited to lower voltages, while the LME49713 current feedback op amp delivers ultra-low distortion, low noise, extended bandwidth past 190 MHz and fast settling times down to 50 nanoseconds.

The dual 5-V LME49721 RRIO op amp maximizes signal integrity by allowing the input signal and output signals to swing within 20 mV of either rail. Its low 4.0 nV/sqrt Hz input referred noise density and 0.0018 percent THD+N make it suitable for lower-voltage supply-rail applications (&plumsn;1.1 V to ±2.5 V) such as 5-V digital-to-analog converters (DACs), portable audio devices, signal conditioning, data acquisition, process control and test equipment.

In addition, the LME49721 provides output current capability up to 100 mA. It is unity-gain stable over a wide supply range of ±1.1 V to 2.75 V, with power-supply rejection rate (PSRR) of more than 100 db and a typical low input bias current of 40 fA. To ensure high dynamic range, it delivers a slew rate of 8.5 V/us while allowing the input signal to drive to the rails.

The single LME49713 current feedback op amp features 1.9 nV/sqrt Hz input noise density, a THD+N of 0.00008 percent and 150-ohm output drive. Its 1900 V/us slew rate ensures accurate bandwidth and high dynamic range for all signal conditioning applications including crosspoint switchers, multimedia broadcast systems, HDTV-compatible systems, line drivers and distribution amplifiers, said National.

The LME49713 is unity-gain stable over a wide supply range of ±5 V to 18 V. Over this supply range, the LME49713 input circuitry maintains a PSRR of more than 100 db and a common-mode rejection rate (CMRR) of 88 dB. The settling time to within 0.1% is 50 ns for a 10-V step.

National is demonstrating its latest high-performance products in booth 744 at the 123rd International Audio Engineering Society Convention in New York City, Oct. 5-8.

Pricing: The LME49721 (8-lead SOIC) is priced at $1.50 each and the LME49713 (8-lead, narrow-body SOIC) is priced at $2.49 each, both in quantities of 1,000.

Product information: LME49713, LME49721 and audio products

National Semiconductor, www.national.com