| 摘要 |
A constant voltage and current supply circuit is provided to simplify a circuit structure by integrating a constant current supply circuit with a constant voltage supply circuit. An amplifier(21) amplifies a signal, which is outputted from a first operational amplifier. A measuring unit(22) measures the signal, which is outputted from the amplifier. First and second DACs(DAC1,DAC2) output constant voltage and constant current operation conditions for the first amplifier. A voltage generation feedback unit(23) outputs a constant voltage condition signal to the first amplifier. A current generation feedback unit(24) outputs a constant current condition signal to the first amplifier, when a signal whose voltage level is lower than a constant voltage level outputted from the second DAC(Digital to Analog Converter). A digital controller outputs the constant current and constant voltage level signals to the first and second DACs. |
