| 摘要 |
A D/A converter in which reference voltage around which voltages outputted vary is not generated by an amplifier in order to reduce electric current consumption. A resistor circuit divides power supply voltage and outputs a plurality of voltages which make up an arithmetic progression. A decoder circuit decodes a digital signal and outputs a control signal. A switching circuit is turned on/off in accordance with the control signal sent from the decoder circuit and selects and outputs one of the plurality of voltages outputted from the resistor circuit. In a conversion circuit, a voltage equal to half of the power supply voltage is obtained by dividing the power supply voltage by resistors and inputted to an inverting input terminal of an operational amplifier which forms a non-inverting amplifier, and the voltage inputted from a switching circuit to a non-inverting input terminal of the operational amplifier is converted into a voltage which varies around a voltage equal to half of the power supply voltage and the converted voltage is outputted. As a result, there is no need to use an amplifier for outputting the voltage equal to half of the power supply voltage and electric current consumption can be reduced.
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