400MSPS，14位1.8伏CMOS直接数字频率合成器AD9954数据表

　　The AD9954 is a direct digital synthesizer （DDS） that uses advanced technology， coupled with an internal high speed， high performance DAC to form a complete， digitally programmable， high frequency synthesizer capable of generating a frequencyagile analog output sinusoidal waveform at up to 160 MHz. The AD9954 enables fast frequency hopping coupled with fine tuning of both frequency （0.01 Hz or better） and phase （0.022° granularity）。 The AD9954 is programmed via a high speed serial I/O port. The device includes static RAM to support flexible frequency sweep capability in several modes， plus a user-defined linear sweep mode of operation. Also included is an on-chip high speed comparator for applications requiring a square wave output. An on-chip oscillator and PLL circuitry provide users with multiple approaches to generate the device’s system clock. The AD9954 is specified to operate over the extended industrial temperature range （see Table 2）。