Press Release Summary:
Offered in 40-pin, ceramic TDIP package, ADSD-1402 includes 2 A/Ds that can be triggered simultaneously or independently. Each input channel has sample-hold amplifier, 2 MHz 14-bit A/D, and its own timing and control circuits. To ensure channel-to-channel matching, A/Ds operate from one precision reference, and there are 2 sets of offset and gain adjustments. Product offers 79 dB signal-to-noise ratio and -80 dB total harmonic distortion.
Original Press Release:
Dual, 14-Bit, 2MHz A/D Converters Feature Independent Operation-No Pipeline Delays
New ADSD-1402 Excels in Multi-Channel, Simultaneous-Sampling and Data "Streaming" Applications
o Functionally Complete:
Two, fast-settling, input S/H amplifiers
Two, 14-bit A/D's with sampling rates to 2MHz
Two, independent timing circuits
Two sets of gain/offset adjustments
One multiplexed output buffer
o Excellent performance:
79dB signal-to-noise ratio
-80dB total harmonic distortion
No missing codes over temperature
o Edge triggering with no pipeline delays
o Small, 40-pin, ceramic TDIP package
o 725mW power from ±5V supplies
o Commercial or mil temp ranges
Simultaneous or Independent Sampling
DATEL's new ADSD-1402 is a single-package, dual, 14-bit, 2MHz sampling A/D converter whose two A/D's can be triggered simultaneously or independently. Each input channel has a fast-settling sample-hold (S/H) amplifier, a 2MHz 14-bit A/D, and its own timing and control circuits. To ensure channel-to-channel matching, the two A/Ds operate from a single precision reference, and there are two sets of offset and gain adjustments.
On the output side, the digital data from the two A/D's are multiplexed through a single output buffer. This conserves package pins and enables data to be "ping-ponged" at two times the sampling rate. With both A/D's converting at the full 2MSPS (megasamples-per-second), output data can be clocked out of the register at 4MSPS.
Lots of Applications
The ADSD-1402 was originally designed for use in high-end imaging (medical, industrial, scientific, military) and two-channel I/Q (in-phase and quadrature) applications in digital receivers. Its uses are expanding rapidly as the availability of low-cost digital processing power makes affordable many apps requiring coherent, simultaneous sampling of multiple-sensor arrays. These include phased-array radars and sonars, x-y detectors, seismic recorders, shock and vibration analyzers, speech digitizers, and FFT/spectrum analyzers.
Edge Triggered, No Delays
The ADSD-1402 is edge triggered. The rising edge of a start-convert signal initiates internal timing that takes care of all functions. No additional clock pulses are required. Output data can be collected from either channel simply by exercising the Enable pins any time after the respective EOC (end of conversion) line activates.
Virtually all other high-speed, high-resolution A/D's require multiple clock pulses before relevant sample data appears at the output. These "pipeline" delays create enormous challenges when trying to mark or keep track of individual samples, especially in multi-channel applications.
"Stream" Data Forever
The ADSD-1402's independent converters, independent timing, and multiplexed outputs enable digitized samples to be collected and continuously "streamed" to mass storage "forever" ... or at least until the memory is full. Eight ADS-1402's, with all 16 of their 14-bit A/D's sampling at 2MHz can deliver 16 x 2 x 14 = 448 megabits (56 megabytes) of sample data per second. That will fill a gigabyte of disc drive in about 18 seconds.
How Do We Do It?
The ADSD-1402 is a multi-chip assembly. It combines numerous active, passive and mixed-signal components in a manner that takes advantage of the best performance characteristics of each. Carefully laid-out signal/return paths, separate ground planes, and local decoupling/filtering, enable the ADSD-1402 to achieve its impressive performance. Signal-to-noise ratio (SNR) is 79dB. Total harmonic distortion (THD) is -80dB. Noise is specified at 250µVrms, and the unit is guaranteed to have no missing codes over its full temperature range.
Package, Power, Temperature
The ADSD-1402 is housed in a small (1.10 X 2.10 inches, 27.44 x 53.34mm), 40-pin, ceramic TDIP (triple-wide, dual-in-line) package. It operates from standard ±5V supplies and consumes a mere 725mW. It is available for operation over either the commercial (0 to +70°C) or military (-55°C to +125°C) temperature ranges. Contact DATEL for additional military high-rel screening.
Price and Delivery
Delivery for either the ADSD-1402MC or ADSD-1402MM models is stock to 2 weeks for evaluation samples or small-quantity orders. Production quantities require 4 to 6 weeks.
Model Number Operating Temp. Range USA Price (100's)
ADSD-1402MC 0 to +70°C $438
ADSD-1402MM -55 to +125°C $586