Low power generation

Analog Devices has developed low-power versions of its TxDAC transmit digital-to-analog converters (DACs).

The AD970x family supports update rates at 175 MSPS (Mega Samples Per Second) – and is comprised of four products: the AD9707 14-bit DAC; and the AD9706, AD9705 and AD9704, which are 12-, 10-, and 8-bit DACs, respectively.

The family features spurious-free dynamic range (SFDR) of 86 dBc and intermodulation (IMD) of 70 to 50 MHz.
All of the devices 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 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 true 14-bit INL (integral nonlinearity) and DNL (differential nonlinearity) performance.

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: a high-speed DAC Pattern Generator (DPG), which provides digital data for ADI’s DAC evaluation boards, and VisualDAC, an integrated development and debugging environment.