| 摘要 |
PURPOSE:To constitute easily a level shift circuit which converts the DC bias voltage into an optional level by using a semiconductor IC and adding a small number of resistances of small resistance value and a buffer amplifier. CONSTITUTION:A voltage attenuation circuit 10 consists of a ladder resistance circuit 11 and a buffer amplifier 12. Both the number of stages of ladder resistances and the combinations of resistance values forming said ladder resistances can be set optionally in order to obtain a desired attenuation factor. In this case, no current flows to a resistance 9 and the circuit 11 when the input signal impressed to a terminal 1 has the DC voltage since the circuit 11 is set between a signal output/input terminal 5 and a bias voltage source 8. Therefore the voltage of the terminal 5 is coincident with the source 8. In other words, the DC bias voltage value of the output voltage can be set optionally by the voltage of the source 8.
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