| 摘要 |
PURPOSE:To obtain a signal having a frequency of about several hundred Hz and to adjust the oscillating frequency by connecting a control MOS transistor (TR) to a source of the MOSTR constituting a ring oscillator. CONSTITUTION:Control P channels 311, 312, 313 are connected between a source and a power terminal of inverter groups 1, 2, 3 constituting a ring oscillator, and control N channels 321, 322, 323 are connected between the drain and the power terminal. Control voltages 51, 52 are applied to gates 331, 332, 333, 341, 342, 343 of each channel TR. In changing the control voltages 51, 52, the leading and trailing time of an output voltage of the inverter groups constituting the ring oscillator are controlled and the duty ratio of an oscillating signal is changed. |
