JPH05341871

PURPOSE:To absolutely and phase-continuously change phases among plural output channels with a high resolution by continuously changing the phases by changing inputted phase data in a DDS used for a waveform output. CONSTITUTION:Phase data 11 and 12, and phase data 21 and 22 are respectively inputted to latch 11 and 21, and latch 12 and 22. The outputs of the latch 11 and 12, and the latch 21 and 22 are respectively added by adders 13 and 23. The outputs of the adders 13 and 23 are respectively integrated by integrators 14 and 24, and the outputs of the integrators 14 and 24 are respectively stored in memories 15 and 25. The outputs of the memories 15 and 25 are respectively D/A converted by D/A converters 16 and 26. A clock control circuit 30 outputs the same reference clock to the latch 11 and 21, the latch 12 and 22, and the integrators 14 and 24. The phases can be continuously changed by changing the phase data 11, 12, 21, and 22. Thus, the phases among the plural channels can be absolutely and phase-continuously changed with the high resolution.