Берешь AD9833(+2.3 V to +5.5 V, Low Power (20 mW), Programmable Waveform Generator in 10-Pin µSOIC Package). У него 0 MHz to 12.5 MHz Output Frequency Range, 28-Bit Resolution (0.1 Hz @ 25 MHz Ref Clock), Sinusoidal/Triangular/Square Wave Outputs, простой 3-Wire SPI® Interface, No External Components Required, 10-Lead MSOP Package. Данные переписаны с сайта analog.com.