NATIONAL SEMICONDUCTOR OPTIMIZES 65MSPS, 12-BIT A/D CONVERTER FOR CELLULAR BASE STATION RECEIVERS

June 1, 1998 - National Semiconductor Corporation® today introduced a 12-bit IF-sampling A/D converter optimized for wireless base station receivers. Operating at 65MSPS, the CLC5956 offers industry leading performance at half the cost of competitive solutions. The CLC5956 is capable of enhancing a variety of non-wireless applications, such as video digitizing, medical imaging and instrumentation, where A/D converters with high resolution, high sampling rate, wide dynamic range, low power dissipation and compact size are required.

With a spurious free dynamic range (SFDR) of 73dBc and 67dB signal-to-noise ratio (SNR) at 5MHz, and 55dBc SFDR and 60 dB SNR at 250 MHz, National's new part offers superior receiver sensitivity in CDMA, GSM and third generation base stations. The CLC5956 has more than 300MHz input bandwidth which simplifies receiver design by directly converting signals at IF frequencies and eliminating expensive amplifiers, analog filters and mixers.

"ADCs can often be the determining factor in base station system performance," said Kurt Rentel, marketing manager for National's High-Speed ADC Group. "With the trend to IF-sampled and wideband radios in base station design, the CLC5956 allows digitization of signals at the first IF, and allows digitization of multiple radio channels, making system design simpler and less costly.

"Also, much of the signal processing that was done in the analog domain in older systems is now done in the digital domain for greater programmability and flexibility. The CLC5956 design enables higher levels of integration in the future, eventually leading to a radio system-on-a-chip," he added.

Since it consumes only 615mW while operating at full speed, the CLC5956 lends itself to the design of low-power receivers while minimizing the need for additional regulation and cooling. The CLC5956 is housed in a 48-pin TSSOP for space-constrained applications and operates from a single 5V power supply.

The CLC5956 features differential analog inputs, low jitter differential PECL clock inputs, a low distortion track and hold, a bandgap voltage reference, TTL compatible CMOS output logic, and a proprietary 12-bit multi-stage quantizer. National offers a CLC5956 evaluation board that facilitates quick bench trials and simplifies final circuit design. The board may be used by simply supplying an analog input signal, encode signal and power from a low noise linear supply. The resulting output is latched 12-bit digital data.

Price and Availability
The CLC5956MTD is priced at $29.80 in 1,000 unit lots in a 48-lead TSSOP (Thin Shrink Small Outline Package). It is available now in production quantities. The order number for a fully loaded evaluation board is CLC5956PCASM. For more information on the CLC5956, visit our World Wide Web site at http://www.national.com/pf/CL/CLC5956.html.

National Semiconductor Corporation produces system-on-a-chip silicon solutions for the information highway, based on its leadership in analog and mixed signal technologies. National is headquartered in Santa Clara, California, and focuses on the communications, personal systems and consumer markets. National has annual sales of approximately $2.5 billion and 13,000 employees worldwide. Additional company and product information is available on the World Wide Web at http://www.national.com.