| 摘要 |
PROBLEM TO BE SOLVED: To perform highly accurate fine adjustment by connecting the output of a digital multiplier to the data input terminal of a D/A converter and correcting a signal to be inputted to the D/A converter while using a fine adjustment control circuit and the digital multiplier in the configuration of outputting analog data to an output terminal. SOLUTION: A reference level generating circuit 108 is located outside a semiconductor integrated circuit, supplies a reference level from a reference level input terminal 113 and impresses it to a D/A converting circuit 102. Besides, the output of a multiplier 103 is impressed to the D/A converting circuit 102 and a full scale is adjusted by a fine adjustment control circuit 107 and the multiplier 103. Three D/A converters 102 are used and respectively take part of R(red), G(green) and B(blue) video signals and digital video signals are converted to analog signals. For example, the number, which can be expressed with eight bits, is from 0 to 255 and in the case of ten bits, the number is from 0 to 1023, but in the case of -5% correction, the numbers from 0 and 969 are used on the condition of 0.95×4=3.8 so that the deviation can be kept almost within 0.1%.
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