Pin-compatible, multichannel ADCs pack speed, resolution

Targeted at high-speed, high-density applications such as basestations, medical imaging, and radar, a family of analog-to-digital converters (ADCs) from Texas Instruments offers choices in channel density, resolution, and signal-to-noise ration (SNR) versus spurious-free dynamic range (SFDR) tradeoff. The ADS6000 family, all pin-compatible, offers two- and four-channel ADCs with 12- or 14-bit resolution, with conversion rates of 80, 105, and 125 Msamples/sec (MSPS)

The AD6425, a 12-bit, quad-channel, 125-MSPS device, is the first member of the family to be released. The vendors specs it at 70.3 dB SNR and 83 dB SFDR at a 50 MHz IF, and it can achieve 86 dB SFDR by adjusting gain. The converters can operate at sampling rates down to near-zero; at full speed, the AD6425 dissipates 420 mW per channel. Outputs are all low-voltage differential signaling (LVDS) for high density and low power.

Housed in 9×9 mm, 64-lead, QFN packages, the converters include user-settable gain for trading a slight increase in SNR for a relatively large increase in SFDR. Similarly, the digitized outputs are LVDS, with single- or dual-stream serial I/O options, to maximize throughput; the serialized LVDS reduces PCB traces by over 60% compared to parallel CMOS I/O. Users can adjust LVDS driver current and internal termination resistors to minimize power consumption at a given operating speed.

ADS6000 Family block diagram

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ADS6000 Family Dynamic Performance

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Since this is a high-speed, high-performance part, appropriate evaluation tools are needed as well. TI offers an evaluation module, and the TSW1200 deserializer card which also includes code examples.

Additional details are

Pricing and availability:
ADS6425 (12-bit, quad, 125 MSPS): available now, $75.25 (1000 pieces)
Other family members (12/14 bit, dual/quad, 80/105/125 MSPS): sampling now
Top end is: ADS6445 (14-bit, quad, 125 MSPS): $132.30 (1000 pieces)
Bottom end is: ADS6223 (12-bit, dual, 80 MSPS): $25.05 (1000 pieces)
Evaluation Module: $299
TSW1200 Deserializer: $649

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