2FSK频率调制用芯片的数据册。The AD9833 is a low power, programmable waveform generator
capable of producing sine, triangular, and square wave outputs.
Waveform generation is required in various types of sensing,
actuation, and time domain reflectometry (TDR) applications.
The output frequency and phase are software programmable,
allowing easy tuning. No external components are needed. The
frequency registers are 28 bits wide: with a 25 MHz clock rate,
resolution of 0.1 Hz can be achieved; with a 1 MHz clock rate,
the AD9833 can be tuned to 0.004 Hz resolution