SANTA CLARA, Calif., 24 May 2010. National Semiconductor Corp. in Santa Clara, Calif., is introducing the ADC12D1800 3.6 giga-sample-per-second analog-to-digital converter for software-defined radio, radar processing, signals intelligence (SIGINT), and electronic warfare applications.
The A/D converter has dynamic performance of -147 dBm/Hz noise floor, 52 dB noise power ratio (NPR) and -61 dBFS intermodulation distortion (IMD) to enable a new generation of software-defined radio architectures and applications, National officials say.
In addition to the ADC12D1800, National introduced two other A/D converters: the ADC12D1600 with sampling speed as fast as 3.2 giga-samples per second and the ADC12D1000 with performance as fast as 2.0 giga-samples per second. All three PowerWise A/D converters are for software-defined radio and related applications like communications, multi-channel set-top box (STB), and light detecting and ranging (LIDAR) applications.
The A/D converter can help radio communications designers come up with new software-defined radio architectures due to the chip's ability to receive modulated, band-limited signals within a large bandwidth. In military radar systems, one ADC12D1X00 combined with a digital down-converter can replace several mixers, filters, amplifiers, and local oscillator stages in traditional heterodyne double- or triple-conversion radio implementations.
The latest class of software-defined radios requires the A/D converter to sample wide-bandwidth signals, so a new set of metrics such as noise-floor, NPR, and IMD provide the best measure of a system’s capability to extract narrowband information from a wideband spectrum, National officials say.
This is in stark contrast to traditional A/D converter specifications -- signal-to-noise ratio (SNR), spurious-free dynamic range (SFDR), and effective number of bits (ENOB) -- which focus on single-tone performance in the Nyquist bandwidth and do not provide the best gauge of a system’s overall capability.
National’s 12-bit A/D converters come in a leaded or lead-free, 292-ball, thermally enhanced BGA package, and are pin-compatible with the ADC10D1000 and ADC10D1500 A/D converters. The 12-bit A/D converters run off a 1.9-volt power supply and consist of two channels that can operate interleaved or as independent channels.
They include circuitry for multi-chip synchronization, programmable gain and offset adjustment per channel. The internal track-and-hold amplifier and extended self-calibration scheme enable a very flat response of all dynamic parameters for input frequencies exceeding 2 GHz, while providing an exceptionally low 10-18 code error rate.
A space-qualified version of the ADC12D1x00 will be supplied in a hermetic 376 column, ceramic column grid array (CCGA) package that meets radiation levels of 120 MeV for single event latch-up and a total ionizing dose of 100 Krads (Si). For more information contact National Semiconductor online at www.national.com.
