| 摘要 |
PROBLEM TO BE SOLVED: To provide a MOS resistance controller which can adapt variable characteristics of a MOS attenuator as requested to absorb any irregular variation and to provide a wireless transmitter using the controller. SOLUTION: The invention includes a MOS transistor having a source connected to a first reference potential, a first control current source inserted and connected between a drain of the MOS transistor and a second reference potential, an operational amplifier having first and second input terminals and an output terminal with the first input terminal being connected to a connection node between the drain of the MOS transistor and the first control current source and the output terminal being connected to a gate of the MOS transistor, an impedance element having one end connected to the second input terminal of the operational amplifier, a reference current source for supplying current to the impedance element through one end, a second control current source for further supplying current to the impedance element through the one end, and a third control current source for supplying current to the drain of the MOS transistor. COPYRIGHT: (C)2009,JPO&INPIT
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