Analog Devices, Inc. has released a 16-bit digital-to-analog converter (DAC) that achieves a sample rate of 1 Giga samples per second (1 Gsps). At these speeds, the converter maintains signal processing performance, offering best-in-class dynamic range, noise and distortion, while consuming up to 36 percent less power than competing solutions, noted ADI. The highly integrated interpolating dual DAC is designed to enable high-quality conversion of the most demanding wireless standards, such as W-CDMA, CDMA2000, TD-SCDMA and WiMAX.

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In addition to the AD9779, ADI is also introducing the AD9778 and AD9776 dual interpolating DACs, forming a family of 16-/14-/12-bit pin-compatible devices that allow designers to easily trade off performance for system cost. These devices are the newest members of Analog Devices' TxDAC+ portfolio of DACs specifically optimized for the transmit signal path of communications systems.

By comparison, the 16-bit AD9779 dual DAC offers 4 dB lower noise, 15 dB better intermodulation distortion (IMD) and 20 dB higher spurious-free dynamic range (SFDR) at a 70 MHz output frequency while consuming 600 mW of power at 500 Msps and 1 W at 1 Gsps. As a dual DAC, gain and offset matching in the AD9779 is guaranteed, making the device appropriate for direct conversion or image reject architectures using an analog quadrature modulator. Integrated gain and offset calibration DACs enable communications equipment designers to optimize sideband rejection and local oscillator (LO) feedthrough in these architectures. For optimized transmit signal chain performance, the analog output of the AD9779 TxDAC+ converter seamlessly interfaces to ADI's analog quadrature modulators, such as the AD8349. A standard parallel interface enables straightforward connection to the AD6633 multichannel wideband upconverter with the VersaCREST crest reduction engine.

The AD9779, AD9778 and AD9776 TxDAC+ converters are sampling now and will be available in production quantities in May 2005 in a Pb-free 100-lead TQFP_EP (Thin Quad Flat Pack_Exposed Paddle) package. The AD9779 is priced at $27.95 in 1000-unit quantities, while the AD9778 and AD9776 are priced at $24.95 and $19.95, respectively, also in 1000-unit quantities.