Direct digital frequency synthesizer using hybrid digital to analog converter and synthesizing method thereof

초록

A direct digital frequency synthesizer and a synthesizing method thereof. The direct digital frequency synthesizer uses a hybrid digital to analog converter, which matches output data of a phase accumulator to a sine wave amplitude using a hybrid DAC, including a non-linear DAC and a linear DAC. The non-linear DAC outputs a direct base point current using some bits of output data of a phase accumulator, causing the linear DAC to output a gradient current based on gradient information generated using other bits of the output data of the phase accumulator. These currents are summed for the analog output.