wirelessZONE Products for the week of September 26, 2005
National Semiconductor Says . . .
ADC08D1500: Dual 8-Bit, 1.5 Gsample/s ADC
Two Additional ADCs Join Gigahertz-range Family
National Semiconductor Corporation expanded its popular family of gigahertz-speed analog-to-digital converters (ADCs) with the introduction of three new converters that offer the industry's best performance with ultra-low power consumption.
The new products are the ADC08D1500, a dual 8-bit converter capable of sampling one analog input at 3 giga-samples per second (GSPS) when operating in dual-edge sampling (DES) mode or two inputs at 1.5 GSPS; the ADC08D500, a dual, 500 mega-samples per second (MSPS) 8-bit converter; and the ADC081500, a single version of the ADC08D1500. These ADCs join the ADC08D1000 and ADC081000, ultra-low-power gigahertz-speed ADCs introduced last year.
"Gigahertz sampling speeds and excellent dynamic performance used
to be synonymous with high power consumption. Today, National is raising
the bar with the first 8-bit ADC capable of sampling signals at 3 GSPS while
consuming a mere 1.9W. This ADC delivers on both performance and low power
consumption," said Antonio Visconti, product line director of National
Semiconductor's Data Conversion Division. "National's ultra-high-speed
data converters stimulate innovation. Every time we increase performance
and sampling speed, we enable new architectures in communications systems
and test and measurement equipment where these ADCs are employed."
analogZONE Says . . .
analogZONE has been tracking this family of parts closely with the single ADC081000 and the later dual ADC08D1000. We are waiting for the clearly intended path for the 08 in the part numbers to change into 10 and then 12… If you are interested in these new parts, all the comments in the previous reviews are still applicable. In particular the continued use of a rail of just 1.9 V must be an analog designer's nightmare in signal handling.
Those previous reviews track the progress of the family against the competing Atmel parts and it is nice to see National increasing the clocking speed without any dramatic increase in power needs, with still less than 2 W. The ENOB has dropped from 7.5 to 7.25 but that is not really significant in operation while the SNR numbers have keep up at very respectable levels. In interleaved mode the full-power bandwidth is a typical 900 MHz. Aperture delay remains at 1.3 ns.
I wouldn't know how to go about pricing parts like this -- does anybody? -- and the increase in pricing from $219 for the ADC08D1000 by 67% for the ADC08D1500 is massive, but I have no idea how real it is. But it is always nice not to have to complain about National giving away parts by leaving money on the table.
This is the kind of adventurous part that makes you want to love National all over again; it will be a simple drop-in for direct RF conversion, T&M and STBs. And I'll be ready to wave the flag high when we get the inevitable 10-bit part.
The ADC08D1500 is in production in a thermally-enhanced LQFP-128 priced at $350 in 1000-piece lots.