The AD9956 is Analog Devices’s firstAgileRF synthesizer. The device is comprised of a DDS and PLL circuitry. The DDS features a 14-bit DAC operating up to 400 MSPS and a 48-bit frequency tuning word. The PLL Circuitry includes a phase detector with scaleable 200 MHz inputs (pre-scalar inputs operate up to 650 MHz) and digital control over the charge pump current. The device also includes a 650 MHz PECL driver with programmable slew rates.The AD9956 uses advanced DDS technology, an internal high-speed, high performance D/A converter and an advance phase-detector/charge pump combination to enable the synthesis of digitally-programmable, frequency-agile analog output sinusoidal waveforms up to 2.7 GHz. The AD9956 is designed to provide fast frequency hopping and fine tuning resolution (48-bit frequency tuning word). Information is loaded into the AD9956 via a serial I/O port which has a device write speed of 25 MBit/sec. The AD9956 DDS block also supports a user defined linear sweep mode of operation.The AD9956 is specified to operate over the extended automotive range of −40°C to +125°C.ApplicationsAgile LO frequency synthesisFM chirp source for radar and scanning systemsAutomotive radarsTest and measurement equipmentAcousto-optic device drivers