AD9954

400 MSPS 14-Bit, 1.8 V CMOS Direct Digital Synthesizer AD9954 FEATURES 400 MSPS internal clock speed Integrated 14-bit DAC Programmable phase/amplitude dithering 32-bit tuning word Phase noise ≤ –120 dBc/Hz @ 1 kHz offset (DAC output) Excellent dynamic performance >80 dB SFDR @ 160 MHz (±100 kHz offset) AOUT Serial I/O control Ultrahigh speed analog comparator Automatic linear and nonlinear frequency sweeping capability 4 frequency/phase offset profiles 1.8 V power supply Software and hardware controlled power-down 48-lead TQFP/EP package Integrated 1024 word × 32-bit RAM Support for 5 V input levels on most digital inputs PLL REFCLK multiplier (4× to 20×) Internal oscillator, can be driven by a single crystal Phase modulation capability Multichip synchronization APPLICATIONS Agile LO frequency synthesis Programmable clock generator FM chirp source for radar and scanning systems Automotive radar Test and measurement equipment Acousto-optic device drivers FUNCTIONAL BLOCK DIAGRAM FREQUENCY ACCUMULATOR DELTA FREQUENCY TUNING WORD DDS CORE 32 RAM DATA 32 FREQUENCY TUNING WORD DELTA FREQUENCY RAMP RATE M U X 32 PHASE ACCUMULATOR Z–1 PHASE OFFSET 32 19 COS(X) AD9954 DAC_RSET 14 DAC IOUT IOUT STATIC RAM 1024 × 32 RAM CONTROL RAM ADDRESS 14 PHASE ACUMULATOR RESET RAM DATA DDS CLOCK 14 Z–1 SYSTEM CLOCK 32 32 10 3 DDS CLOCK MUX SYNC_IN θ OSK PWRDWNCTL RAM DATA 14 <31:18> TIMING AND CONTROL LOGIC I/O UPDATE M U X 0 SYNC SYNC_CLK ÷4 CONTROL REGISTERS COMPARATOR C...