| 摘要 |
PROBLEM TO BE SOLVED: To provide a means which is capable of maintaining a negative bias and taking measures to cope with spurious without requiring any operating clock, that is output of an oscillator, when operating an antenna switch circuit. SOLUTION: A level shift circuit 15 of a switching control circuit 1 which outputs a signal to a gate terminal of an antenna switch transistor to be used for changing over an antenna switch includes a level shift latch. The level shift latch maintains a negative potential, thereby supplying a negative bias to the gate terminal. Furthermore, differently from a charge pump, without requiring any operating clock, the level shift latch suppresses spurious mainly caused by a higher harmonic wave of the clock. COPYRIGHT: (C)2011,JPO&INPIT
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