METHOD AND DEVICE FOR ENLARGING DYNAMIC RANGE WITHOUT SPURIOUS RADIATION FOR DIGITAL/ANALOG CONVERTER

摘要

PROBLEM TO BE SOLVED: To execute SFDR enlargement without spurious radiation by generating an analog signal converted within the dynamic range (SFDR) of a first digital/analog converter(DAC) on a first route. ;SOLUTION: A DAC system 10 route-designates a first part in a digital signal S, namely, a part which is amplitude-restricted on a first route 16 against DAC 12. DAC 12 converts it into an analog system. The number of lowest bits in the digital input signal S which is route-designated against second DAC 14 reflects the clipping quantity of the amplitude on the digital input signal S. When the number of LSB, which is route-designated, is large, the clipping of the digital input signal S increases and the amplitude of composite signals S and D which are route-designated against first DAC 12 becomes small. The composite digital signal S of small amplitude with signal distortion D is supplied to first DAC 12 and a relatively small spurious distortion level is generated in an output signal level.;COPYRIGHT: (C)2000,JPO