Mixed Signal/Analog
Analog Devices Unveils Continuous-time Sigma-delta ADC Family
Analog Devices has unveiled what it says is the industry’s lowest noise, widest bandwidth family of continuous-time sigma-delta (CTSD) analogue-to-digital converters (ADCs) today. The 16-bit, AD9261 and AD9262 CTSD converter, and the AD9267 CTSD modulator couple low noise and high dynamic range with a bandwidth of up to 10 MHz.
The “Today’s electronics increasingly rely on data conversion to faithfully translate digital information to provide the images, voice, audio, video and other real-world content that defines the quality of the end-user experience,” said Susie Inouye, research director, Databeans Inc.
“While other architectures have pushed the performance envelope by offering exceptional throughput, high dynamic range or excellent low-noise characteristics, CTSD excels in all of these areas.”
The new converters complement Analog Devices’ data converter portfolio providing exceptionally wide bandwidth and low noise. The highly integrated CTSD architecture eliminates multiple discreet components at the system level, while simultaneously improving performance and simplifying product development.
Pipeline and SAR ADC architectures are common analog architectures today. Pipeline ADCs are typically used for wireless infrastructure, video processing and other applications where performance requirements dictate wide bandwidth. SAR ADCs are usually used for industrial controls and data acquisition systems where precision and low-noise are key performance factors. Until now, a performance gap existed today between pipeline and SAR ADCs because there were no converters that could meet the conversion needs of emerging technologies that simultaneously demand high dynamic range, wide bandwidth and low power. The AD926x CTSD ADCs fill this performance gap by efficiently delivering wide bandwidth and greater accuracy while significantly reducing system level complexity.
The AD926x utilizes principles of over sampling, noise shaping and input characteristics unique to its architecture to achieve high levels of performance and ease of use. The quiet resistive input structure relaxes the requirements of the driver amplifier while the higher order over-sampled continuous time loop filter attenuates out-of-band signals reducing the need for large baseband filters and other signal conditioning circuitry. The high dynamic range performance reduces or eliminates the need for automatic gain control in many applications. These features coupled with a wide input bandwidth simplify system design, reducing the overall system footprint and shortening time-to-market. By offering design engineers a choice of ADC architectures, ADI can support any signal chain regardless of whether performance requirements demand high speed, precision, low power or any combination of the three.
The 16-bit single and dual AD926x ADC family achieves industry leading performance with an unprecedented combination of 86-dB dynamic range for an input signal bandwidth of up to 10MHz. The highly integrated AD9261 and AD9262 feature an on-chip PLL clock multiplier, decimation filters, and sample rate converters and provide flexible output data rates between 30 MSPS (mega-samples-per-second) and 160 MSPS. The AD9267, which features only the high performance 640-MSPS modulator core and PLL clock multiplier, presents the high speed data directly to the output. This provides designers the flexibility to offload signal processing functions to an FPGA or other processor. The 150-mW per channel to 350-mW per channel power consumption of the new CTSD converters is matched to a range of communications and industrial applications, including emerging radio architectures, such as direct down conversion, where the dual AD9262 and AD9267 can be used to support multiple wireless carriers and standards simultaneously.