400 MSPS, 14-Bit, 1.8 V CMOS Direct Digital Synthesizer

The AD9953 is a direct digital synthesizer (DDS) featuring a 14-bit DAC operating up to 400 MSPS. The AD9953 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 sinusoidal waveform at up to 200 MHz. The AD9953 includes an integrated 1024 × 32 static RAM to support flexible frequency sweep capability in several modes. The AD9953 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 AD9953 via a serial I/O port.

The AD9953 is specified to operate over the extended industrial temperature range of –40°C to +105°C.

Applications

* Agile VHF/UHF LO frequency synthesis

* FM chirp source for radar and scanning systems

* Nonlinear-shaped PSK/FSK modulator

* Test and measurement equipment

* 400 MSPS internal clock speed

* Integrated 14-bit DAC

* 32-bit tuning word

* Phase noise ≤ –120 dBc/Hz at 1 kHz offset (DAC output)

* Excellent dynamic performance:

>80 dB SFDR at 160 MHz (±100 kHz offset) AOUT

* Serial input/output (I/O) control

* 1.8 V power supply

* Software and hardware controlled power-down

* 48-lead TQFP/EP package

* PLL REFCLK multiplier (4× to 20×)

* Internal oscillator, can be driven by a single crystal

* Phase modulation capability

* Multichip synchronization