The software-defined radio (SDR) is commonplace today and its use is expanding. What makes SDR possible is a fast analog-to-digital converter (ADC) with good resolution. While such ADCs are available, many are inherently power hogs. Now Texas Instruments is fixing this problem with its ADS4149 low-power ADC.

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The ADS4149 is the first in a new series of high-speed ADCs that have ultra-low power consumption and excellent dynamic performance across wide signal bandwidths from dc up to 550 MHz. It has a maximum sample rate of 250 Msamples/s and 14-bit resolution, and it consumes 30% less power than comparable devices while delivering 3-dB greater signal-to-noise ratio (SNR) than the nearest low-power ADC.

This combination improves efficiency and density while enhancing range and sensitivity in military man-pack radios, defense systems, test and measurement, and similar communications applications. The ADS4149 also looks like a good choice for the ADC in the feedback path for a digital pre-distortion compensation circuit for high-linearity power amplifiers.

The ADS4149 consumes as little as 275 mW per channel at 250 Msamples/s, while offering 72.5-dB SNR at 100-MHz input frequency. Dynamic power scaling reduces power consumption to 215 mW at 160 Msamples/s. An optional buffered analog input version provides constant input impedance across time and frequency and eliminates sample-and-hold kickback, simplifying input matching for passive and active analog front ends while reducing pass-band ripple.

A 1- to 6-dB programmable gain option gives customers flexibility to trade off between SNR and spurious free dynamic range (SFDR) with lowered input voltage swing. The migration path from the higher-power ADS6149 allows customers to shift to lower power options. The ability to use TI’s TWS1200 digital capture tool facilitates rapid analysis of the ADS4149’s evaluation module (EVM). An available high-speed HSMC mezzanine connector and FMC FPGA mezzanine connector allow ADS4149 EVMs to mate to FPGA EVMs for system-level prototyping to speed development time.

The ADS4149 is part of a family that includes pin-compatible 12- and 14-bit options at 160 and 250 Msamples/s and buffered devices to enable customers to easily move to lower resolutions and sample rates without altering their core design. The ADS4149 and companion single-configuration parts are available today in a 48-pin quad flat no-lead (QFN) package. The ADS4149 costs $89 in 1000-unit quantities. The buffered version and other devices in the series will be available in early 2010.