Date: 08/11/2008
10 bit 2GSPS ADC and a 2.5 GHz fully differential amplifier
ADC10D1000 from National Semiconductor is a 10-bit, 2 Giga-sample per second (GSPS) single/1 GSPS dual analog-to-digital converter (ADC). The suitable applications for this device are ground-based radar, data acquisition systems, point-to-point base stations and next-generation set-top boxes.
At a frequency of 248 MHz, the ADC10D1000 provides the best spurious-free dynamic range (SFDR) performance of 66 decibels relative to carrier (dBc) and 9.1 effective number of bits (ENOB).
Another companion for this ADC, a 2.5 GHz LMH6554 wideband, fully differential amplifier drives the 10-bit ADC10D1000, offer 0.1 dB gain flatness up to 800 MHz, SFDR of 72 dBc at 250 MHz and leading low-input voltage noise performance of 0.9 nV/sqrt Hz.
The ADC10D1000 yields 2.52 picojoules (pJ) per conversion, while the LMH6554 consumes 21 uA per MHz.
With the best SFDR and ENOB, ADC10D1000 enables digitization of wide swaths of bandwidth in applications that have previously had to use narrowband ADCs to achieve high-resolution sampling. For example, high-resolution radar systems now can use fewer parallel channels to digitize the same bandwidth, enabling significantly reduced board size and power dissipation. Due to its low power consumption, designers can do away without using heat sinks.
The ADC10D1000 digitizes a pair of analog input signals at sampling rates up to 1 GSPS, or a single analog input signal at speeds up to 2 GSPS. Additional features include AutoSync for multi-chip synchronization and programmable gain and offset adjustment for each channel. The internal track-and-hold amplifier and the extended self-calibration scheme enable a very flat response of all dynamic parameters beyond Nyquist, while providing an exceptionally low 10 (-18) code error rate.
Package: The ADC10D1000 is supplied in a leaded or lead-free, 292-ball, thermally enhanced BGA package.
The LMH6554 is a 2.5 GHz fully differential amplifier that provides desired signal fidelity for driving 8- to 16-bit high-speed ADCs. The device's low impedance differential output is designed to drive ADC inputs and any intermediate filter stage. The LMH6554 delivers 16-bit linearity up to 75 MHz when driving 2V peak-to-peak into loads as low as 200-Ohms. With external gain set resistors and integrated common-mode feedback, the LMH6554 can be used in differential-to-differential or single-ended-to-differential configurations. The amplifier provides large signal bandwidth up to 1.8 GHz, 8 dB noise figure and a slew rate of 6200 V/us.
Pricing and Availability
The ADC10D1000 and LMH6554 are sampling now, with production quantities scheduled for first quarter 2009.
For more information on the ADC10D1000's pricing, samples and reference boards, visit www.national.com/pf/DC/ADC10D1000.html.
The LMH6554 is priced at $4.50 in 1,000-unit quantities. For more information, or to order samples, visit www.national.com/pf/LM/LMH6554.html.
A space-qualified version of the ADC10D1000 will be available in the first quarter of 2009. It will be supplied in a hermetic 376 column, thermally enhanced, ceramic column grid array (CCGA) package. The space-level version meets radiation levels of 120 MeV for single event latch-up and a total ionizing dose of 300 Krads (Si), making it well-suited for wideband satellite communications. Samples of the CCGA version are available now for evaluation.