| 摘要 |
A high-precision and high-performance level shift circuit is provided, which is not adversely influenced by an offset error owned by an operational amplifier, and an output dynamic range of a digital/analog converter of a signal source. Since two sets of resistors 4o and 4p having the same resistance values to each other, which are connected between differential output terminals, and also, an operational amplifier 4r for performing a level shift control are provided, a feedback operation is carried out in such a manner that an average voltage of each of differential outputs 4i and 4m is continuously made coincident with a DC reference potential 4q irrespective of an offset error of an output-purpose operational amplifier, and a level shift function having a small error is realized. Also, since a resistor 4h and another resistor 4l are series-connected between a differential output of a digital/analog converter 4a and a level shift circuit, such a voltage can be outputted outside an output dynamic range of the digital/analog converter 4a.
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