Circuit arrangement of voltage controlled oscillator

Claim 2

A circuit arrangement of voltage controlled oscillator comprising: a voltage controlled oscillator circuit part for generating a signal of a frequency proportional to an input control current; a first constant-current circuit for causing a predetermined constant current to flow; current dividing means for dividing said constant current of the first constant-current circuit in accordance with a control voltage applied from the outside; and a second constant-current circuit for causing a predetermined constant current to flow, the oscillation frequency of said voltage controlled oscillation circuit part being controlled by said input control current equal to the sum of one divided current divided by said current dividing means and the constant current of said second constant-current circuit.

Claim 3

A circuit arrangement of voltage controlled oscillator comprising: a voltage controlled oscillator circuit part for generating a signal of a frequency proportional to an input control current; a first constant-current circuit for causing a predetermined constant current to flow; current dividing means for dividing said constant current of the first constant-current circuit in accordance with a control voltage applied from the outside; and a second constant-current circuit for causing a predetermined constant current to flow, the oscillation frequency of said voltage controlled oscillation circuit part being controlled by said input control current equal to the sum of one divided current divided by said current dividing means and the constant current of said second constant-current circuit.

Claim 4

A circuit arrangement of voltage controlled oscillator comprising: a voltage controlled oscillator circuit part for generating a signal of a frequency proportional to an input control current; a first constant-current circuit for causing a predetermined constant current to flow; current dividing means for dividing said constant current of the first constant-current circuit in accordance with a control voltage applied from the outside; and a second constant-current circuit for causing a predetermined constant current to flow, the oscillation frequency of said voltage controlled oscillation circuit part being controlled by said input control current equal to the sum of one divided current divided by said current dividing means and the constant current of said second constant-current circuit.

Claim 5

A circuit arrangement of a voltage controlled oscillator as claimed in claim 1 in which said current dividing means comprises a differential amplifier including a pair of transistors on whose respective bases control voltages are applied.

Claim 6

A circuit arrangement of a voltage controlled oscillator as claimed in claim 1 in which said current dividing means divides an output current I1 of said first constant-current circuit within a range of from zero to I1, and the input of said voltage controlled oscillator circuit part is varied within a range of + or - 1/2 I1 about (I2 + 1/2 I1) as a center (where I2 is an output current of the second constant-current circuit).

Claim 7

A circuit arrangement of a voltage controlled oscillator as claimed in claim 1 in which said voltage controlled oscillator circuit part comprises: a pair of transistors having respective emitters connected together and receiving said input control current passed therethrough, said transistors alternately repeating ON and OFF operations; means operating in accordance with said ON and OFF operations of said transistors to vary the base potential of one of said transistors between two mutually different potentials; a resistor of high resistance value connected to the base of said one of said transistors, the other of said transistors being connected to a capacitor for repeatedly charging and discharging with respect to the base of said other transistor; and means for causing charging and discharging currents of currents of current values equal to the current value of driving means to flow in said capacitor.

Claim 8

A circuit arrangement of a voltage controlled oscillator as claimed in claim 4 in which: said circuit arrangement is incorporated within a single integrated circuit; said capacitor is outside of said integrated circuit; and the integrated circuit has a terminal for connecting the capacitor to the base of said other of the transistors.

Claim 9

A circuit arrangement of a voltage controlled oscillator as claimed in claim 1 in which said first contant-current circuit comprises a current mirror circuit for flowing equal currents respectively through two output ends thereof, one of said output ends being connected to said current dividing means, and there is further provided with a pair of control terminals on which the control voltage from the outside is applied, said control terminals, in a state wherein the potentials thereof are maintained substantially equal, being connected to means for varying the current of the other of said output ends of current mirror circuit.