The AD9858 is a direct digital synthesizer （DDS） featuring a 10-bit digital-to-analog converter （DAC） operating up to 1 GSPS. The AD9858 uses advanced DDS technology coupled with an internal high speed， high performance DAC to form a digitally programmable， complete high frequency synthesizer capable of generating a frequency-agile analog output sine wave at up to 400 MHz. The AD9858 is designed to provide fast frequency hopping and fine tuning resolution （32-bit frequency tuning word）。 The frequency tuning and control words are loaded into the AD9858 via parallel （8-bit） or serial loading formats. The AD9858 contains an integrated charge pump （CP） and phase frequency detector （PFD） for synthesis applications requiring the combination of a high speed DDS along with phase-locked loop （PLL） functions. An analog mixer is also provided on chip for applications requiring the combination of a DDS， PLL， and mixer， such as frequency translation loops and tuners. The AD9858 also features a divide-by-2 on the clock input， allowing the external reference clock to be as high as 2 GHz. The AD9858 is specified to operate over the extended industrial temperature range of –40°C to +85°C.