| 摘要 |
PURPOSE:To make the on resistance of a switch constant and to reduce distortion by applying a bias voltage equal to an analog signal voltage to the substrate electrode of an MOS type field effect transistor (FET) which constitutes the switch. CONSTITUTION:When a clock signal phi has a level H and its signal phi' has a level L, MOSFETs 1 and 2 both turn on. Then, an input signal IN is transferred to an output terminal 4 through the MOSFETs 1 and 2 and an output signal OUT is applied to the gate of an MOSFET5. When the voltage of the input signal IN is high enough, the voltage between the source of the MOSFET1 and the substrate electrode is equal to the threshold voltage of the MOSFET5 and when the voltage of the input signal IN is low enough, the voltage is nearly zero. Therefore, the on resistance of the switch composed of the MOSFETs 1 and 2 less varies. |
