Analog Devices Unveils Low-Power, Transmit-Quality, High-Speed Digital-To-Analog Converters

Analog Devices AD9707

Fourth-generation, low-power TxDAC® digital-to-analog data converters for communications, industrial instrumentation and portable applications

Analog Devices announced the company has developed a low-power generation of its industry-leading TxDACВ® transmit digital-to-analog converters (DACs). Optimized to the requirements of communications, industrial instrumentation and portable applications that require high-speed performance with the lowest power consumption, Analog Devices' AD970x family reduces power dissipation by up to 70 percent over previous DAC offerings. As a transmit-quality converter, the AD970x family is ideal for applications that need to synthesize broadband signals efficiently- from handheld radios to portable instruments.
AD9707 digital-to-analog converter
In addition, the AD970x family integrates an on-chip voltage reference and Rset and Rload resistors, lowering component count and bill of materials costs. The devices also feature common mode shift capability, minimizing the need for level-shifting circuitry when interfacing with other analog components. This level of integration, the first of its kind for transmit path data converters, simplifies analog design and reduces printed circuit board area for smaller portable designs.

"Analog Devices' TxDAC products have become the de facto industry standard for transmit path DACs," said Dave Robertson, product line director of the High-Speed Converter Group at Analog Devices. "These new devices are pin compatible with previous generations of the TxDAC family, enabling designers to take advantage of the dramatic decrease in power dissipation without the need for a costly re-design. The AD9707 family is the latest of a series of new products from ADI focused on lowering overall system cost without performance compromise. It provides the signal path solution while our nanoDACTM family provides low power DACs for level setting and control applications."

More about the AD970x family
The AD970x family supports update rates at 175 MSPS (mega samples per second) - an operating rate four times that of its nearest competitor with similar power dissipation - and is comprised of four products: the flagship AD9707 14-bit DAC; and the AD9706, AD9705 and AD9704, which are 12-, 10-, and 8-bit DACs, respectively. The family features best-in-class spurious-free dynamic range (SFDR) of 86 dBc and intermodulation (IMD) of 70 to 50 MHz.

All of the devices offer outstanding ac and dc performance and share the same interface, small outline package and pin-out, providing an upward or downward component selection path based on performance, resolution, and cost.

The AD9707 has a flexible power supply operating range from 1.7 V to 3.6 V. At 3.3 V, the AD970x family dissipates 35 mW of power and at 1.8 V dissipates 12 mW. Its power dissipation can be further reduced by 15 mW by lowering the full-scale current output. Sleep and power down modes reduce dissipation to 5 mW for low-power idle periods.

The devices are available in 28-lead TSSOP (thin-shrink small-outline plastic package) and 32-lead LFCSP (lead-frame chip-scale package) packaging. The devices in the LFCSP packaging include an optional SPI (serial peripheral interface), which provides a higher level of programmability, and an adjustable output common mode feature that enables the TxDAC to easily interface to other components that require common modes greater than 0 V. The AD9707 is also self-calibrating, allowing it to achieve greater accuracy and true 14-bit INL (integral nonlinearity) and DNL (differential nonlinearity) performance.

Pricing and Availability
The AD970x family is sampling now with production quantities available in October 2005. Pricing for the family ranges from $2.75 to $5.75 in 1,000-unit quantities, depending on resolution. The devices are supported by an evaluation board and two development tools: the high-speed DAC Pattern Generator (DPG), which provides digital data for ADI's DAC evaluation boards, and VisualDACTM, an integrated development and debugging environment.