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The Analog Devices AD9122 digital-to-analog converter (DAC) supports the high data rates and complex modulation schemes required for advanced multi-carrier wireless and broadband communications equipment throughout the world, according to the company. This dual-channel, 16-bit device features an on-chip 32-bit numerically controlled oscillator (NCO) that allows flexible placement of the intermediate frequency (IF) to help optimize system performance.

The DAC meets the requirements for GSM, WCDMA, TD-SCDMA, cdma2000, WiMAX, and LTE operation. Combined with the company’s ADL5375 quadrature modulator and AD9516 14-output clock generator, it meets or exceeds six multi-carrier GSM specifications for intermodulation distortion (IMD) and signal-to-noise ratio (SNR). The signal chain is available as an evaluation board. Other complementary parts include the ADRF6702 quadrature modulator and the ADRF6602 receiver mixer.

The AD9122 low-voltage differential signaling (LVDS) interface, which has a first-in, first-out (FIFO) memory that’s eight words deep, supports a maximum sample data input rate of 1.2 Gsamples/s and 600 Msamples/s per DAC to support signal bandwidths to 400 MHz in advanced digital pre-distortion (DPD) transmitter architectures. The data interface supports word, byte, and nibble load, so customers can reduce input pins on lower data rates to save board space, power, and cost.

An improved on-chip phase-locked loop (PLL) offers lower jitter and phase noise. Operating with the on-chip PLL at a DAC output frequency of 150 MHz, the AD9122 delivers a 760-dB adjacent-channel leakage ratio (ACLR) for single-carrier WCDMA applications. The DAC also can achieve an 83-dBc ACLR using an external PLL for the most demanding wireless communications applications.

The combination of input data rates, high DAC sample rates, and fine modulation with the integrated NCO gives system designers flexibility in choosing DAC output frequencies, Analog Devices says. This is especially helpful in meeting four- to six-carrier GSM transmission specifications and other communications standards, the company also says. And, the device’s integrated interpolation filters include selectable interpolation factors of two, four, and eight.

Meanwhile, the Analog Devices Data Pattern Generator (DPG2) benchtop instrument can be used to drive vectors into the company’s high-speed DACs. It connects to a PC over USB and lets users download vectors from their PC into its internal memory. Once downloaded, the DPG2 can run the vector at full speed via an attached evaluation board for a specific DAC. This allows for rapid evaluation of the DAV with both generic and customer-generated test data.

The AD9122 is available in a 72-pin lead-frame chip-scale package that’s 50% smaller than previous DACs. Available now, it costs $34.95 each in lots of 1000.