| 摘要 |
A cascode-connected amplifier circuit, a semiconductor IC(Integrated Circuit), and a receiving apparatus using the same are provided to receive voltage applied to a base terminal of the first transistor or a gate terminal of the FET to stop the operation of the cascode-connected amplifier circuit exactly even though a first transistor or an FET(Field Effect Transistor) is operated. In a cascode-connected amplifier circuit(1), an emitter-grounded first transistor(Q1) or a source-grounded first FET and a base-grounded second transistor(Q2) or a gate-grounded second FET are cascode-connected. A selection unit(SW1) selects whether to ground a collector terminal of the first transistor or a drain terminal of the first FET. A first voltage control unit(V1) controls voltage applied to a base terminal of the second transistor or a gate terminal of the second FET. In executing grounding by the selection unit, the first voltage control unit controls base voltage of the second transistor or gate voltage of the second FET and reduces current flowing in the second transistor or the second FET.
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