| 摘要 |
PROBLEM TO BE SOLVED: To remarkably reduce an IC chip area, accordingly, costs for providing a D/A converting circuits by minimizing all the capacity values of a capacitive D/A converting circuit having the digital input (resolution) of about 8 to 16 bits. SOLUTION: Analog switches S [S1 (MSB)-S12 (LSB)] are respectively correspond to the respective bits of 12-bit digital input and corresponding to whether the relevant bit is '1' or '0', a reference voltage source Vref is respectively switched to the ground. A Vout is an analog output terminal. A capacitor stream 1 is composed of six stages 11-16, namely, the number of (digital input bit number/2) and a coupling capacitor 2 is composed of five steps 21-25. Then, each capacitor now 1 is composed of two capacitors of capacity values C and 2C and the coupling capacitor 2 is composed of the capacitor of a capacity value 4C/3.
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