| 摘要 |
PURPOSE:To attain the circuit integration of an element whose oscillated frequency is changed in one IC chip by inserting an MOS transistor (TR) in series with a path to make a pulse delay time variable in an inverter section. CONSTITUTION:A ring oscillator is constituted by connecting CMOS inverters 1, 2, 3 in series, a P-channel MOSFET14 and an N-channel MOSFET15 are inserted to a path between the inverters 2 and 3 and a control voltage is applied to each gate terminal G of the FETs 14, 15. The control voltage is changed to change the time constant and delay time of the parallel circuit comprising the N-channel MOSFET13 or the P-channel MOSFET12 and the FETs 14, 15 thereby controlling the oscillated frequency. Thus, it is possible to integrate all the oscillators on one chip IC thereby decreasing number of components. |
