| 摘要 |
PURPOSE:To decrease leakage to an output side by constituting the titled switch as longitudinal stack differential 2-stage, controlling signal on/off of the differential stage of upper stage and using the lower stage differential stage to convert linearly an input signal thereby avoiding direct leakage of the input signal via a parasitic capacitance. CONSTITUTION:When VC>VR2, almost no current flows to a transistor (TR)Q22, an output Vout becomes a nearly constant value, and the switch is turned off. On the other hand, when VC<VR2, almost no current flows to a TRQ21, and the output Vout is VCC-RLia, where RL is a resistance value of a resistor R21 and ia is a current flowing to the TRQ22, changes linearly to an input signal and the output Vout is nearly linear to the input. When the switch is turned on, no direct leakage exists via a parasitic capacitance of the input signal VIN, the change in the VIN appears as the change in the VBE of the Q21 and this change is leaked to the output side via a base-emitter and a base-collector junction capacitance. |
