| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor device where a power amplifier preventing destruction by counter electro-motive force, which occurs in an inductor without deterioration of an amplification characteristic, and a power amplifier bias circuit are realized. SOLUTION: A diode 9a is connected to a bias line 5 connecting a collector terminal and a power terminal 6 of a bipolar transistor 2 so that an anode comes to a collector terminal-side. When runaway starts in a certain cell, the diode 9a clips counter electromotive voltage so as to lower it. Thus, large voltage on the bipolar transistor 2 is suppressed. In a stage where runaway does not occur, loss by a resistance component is eliminated in a course supplied to a base terminal and consequently, conventional deterioration of output power at the time of high output is suppressed. COPYRIGHT: (C)2007,JPO&INPIT
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