Analog Devices Introduces Eight High-speed, Low-power DACs

5th November 2008

Analog Devices

ES Admin

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Analog Devices has introduced eight TxDAC transmit digital-to-analogue converters (DACs), each integrating two DACs on a single device. Adding to ADI’s extensive high-speed DAC portfolio, the new pin-compatible dual TxDAC converters are designed for communications, industrial, instrumentation and other demanding high-performance applications for which low power consumption and space savings yield significant cost, performance and time-to-market advantages. Dissipating only 220 mW at their maximum sample rate, the AD911x series of dual TxDAC devices consume 40 percent less power and are one-third the size of competing transmit DACs, while achieving 10 dB better SFDR (spurious-free dynamic range) performance. The AD971x series of dual TxDAC devices, with 2-mA full-scale output current, are even more energy efficient, consuming 70 percent less power than competing solutions.

“With the industry increasingly focused on efficiency and portability, design engineers are being squeezed to reduce power consumption and board space in their designs,” said David Robertson, product line director for the High Speed Signal Processing group, Analog Devices. “Whether they’re designing femtocell base stations, battery-powered instrumentation or medical applications, designers are looking for new DAC products that will help them meet their space and power budgets, without sacrificing performance.”

Each new TxDAC integrates two 14-, 12-, 10- or 8-bit digital-to-analogue converters with sample rates up to 125 MSPS (mega-samples-per-second). These devices allow designers to adjust the full-scale current from 1 to 4 mA or 4 to 20 mA with a single, pin-compatible architecture and common software code.

The AD971x TxDAC series features 1- to 4-mA maximum differential output current. Power dissipation at 2 mA output current is only 37 mW at 10 MSPS and 53 mW at 50 MSPS. This is one-third that of competing transmit DACs, making the new series ideal for small, limited range wireless equipment, such as picocell and femtocell base stations and battery-powered medical, industrial and instrumentation applications.

The AD911x TxDAC series has 4- to 20-mA maximum differential output current. It dissipates 40 percent less power than other devices in its class and is suited to automotive, medical, instrumentation and communications applications where channel densities must be maximized without the addition of cooling fans or where environmental considerations are driving a reduction in power consumption. The AD911x devices achieve 85-dB SFDR to 10 MHz, which is superior to other devices in its class.

Despite their small 6 mm x 6 mm package size, the new DACs are loaded with performance features, such as an internal calibrator for improved INL and DNL performance up to a 10-MHz output frequency, an internal voltage reference, independent full-scale current control, on-chip load and common-mode resistors, and a pair of auxiliary DACs that can be used for generating control voltages or for system calibration.

The new TxDAC devices offer a seamless interface to ADI’s high-performance quadrature modulators, such as the ADL5370. If a single-ended or differential-buffered voltage output is needed, then the ADA4899-1 and ADA4841-2 operational amplifiers are excellent choices, respectively. Additionally, Analog Devices’ high speed converters, such as the AD911x TxDAC family, are designed to operate seamlessly with ADI’s AD9513 clock distribution IC and new line of voltage regulators, including the ADP3334 and ADP3333.