The AD9956 is Analog Devices’s first AgileRF synthesizer.The device is comprised of a DDS and PLL circuitry. The DDSfeatures a 14-bit DAC operating up to 400 MSPS and a 48-bitfrequency tuning word. The PLL Circuitry includes a phasedetector with scaleable 200 MHz inputs (pre-scalar inputsoperate up to 650 MHz) and digital control over the chargepump current. The device also includes a 650 MHz PECL driverwith programmable slew rates.The AD9956 uses advanced DDStechnology, an internal high-speed, high performance D/Aconverter and an advance phase-detector/charge pumpcombination to enable the synthesis of digitally-programmable,frequency-agile analog output sinusoidal waveforms up to2.7 GHz. The AD9956 is designed to provide fast frequencyhopping and fine tuning resolution (48-bit frequency tuningword). Information is loaded into the AD9956 via a serial I/Oport which has a device write speed of 25 MBit/sec. The AD9956DDS block also supports a user defined linear sweep mode ofoperation.

The AD9956 is specified to operate over the extendedautomotive range of −40°C to +125°C.

This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.