| 摘要 |
PURPOSE:To obtain a voltage controlled oscillation circuit while the stabilized operation is realized by detecting the self-running oscillation frequency when a prescribed control is applied and applying additively a constant current according to the difference with a set self-running oscillation frequency to a variable current. CONSTITUTION:Each conductance ratio is set in MOSFETs Q2-Q5 so that they have a current weight according to a binary signal stored in a latch circuit FF. When outputs of the circuit FF are all at low level, the FETs Q2-Q5 flow currents i1-i14 according to a constant voltage V0 and its conductance, they are added to a control current IC to increase the charging current to capacitors C1, C2 thereby increasing the self-running frequency. When the outputs of the circuit FF are all at high level, the FETs Q2-Q5 are all turned off because of the high source potential regardless of the supply of the voltage V0 to the gates and only the current IC actslike a charging current. The provision of the compensation circuit in this way allows an objective oscillation frequency at the midpoint potential of the control voltage.
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