Voltage controlled oscillator with temperature compensating bias source

Claim 2

A voltage controlled oscillator responsive to the magnitude of an input control signal for producing a frequency related to such magnitude comprising: a semiconductive substrate; a multivibrator having timing capacitor means; current source means integrated into said substrate, coupled to said capacitor means, and responsive to said control signal for determining the frequency of oscillation of said multivibrator. and a temperature dependent network integrated into said substrate for biasing said current source means, said network including balanced bridge means having a center leg carrying negligible current for providing a biasing voltage for said current source means.

Claim 3

A voltage controlled oscillator as in claim 1 where said biasing voltage has a predetermined temperature coefficient to substantially balance temperature caused shifts in said current source means thereby providing a zero temperature coefficient.

Claim 4

A voltage controlled oscillator as in claim 1 where said balanced bridge means includes two parallel branches having equal currents, at least one of said branches having series diode means having a predetermined change of voltage drop with temperature.

Claim 5

A voltage controlled oscillator as in claim 3 where said branch with said diode means includes a series connected resistor and where the magnitude of said equal currents is equal to the ratio of the voltage drop across the diode means and the value of said resistor, said center leg being connected to the junction of said resistor and diode means.

Claim 6

A voltage controlled oscillator as in claim 4 where the other parallel branch includes two series connected resistors each having a value equal to said resistor in said branch with said diode means, said center leg being connected to the junction of said series resistors.

Claim 7

A voltage controlled oscillator responsive to the magnitude of an input control signal for producing an output signal having a frequency related to such magnitude comprising: a semiconductive substrate; a multivibrator having timing capacitor means, the charging and discharging of said capacitor means determining the frequency of oscillation of said output signal of said oscillator; current source means integrated into said substrate, coupled to said capacitor means, and respoNsive to said control signal for determining the frequency of oscillation of said multivibrator; and a temperature dependent network integrated into said substrate for biasing said current source means to provide a predetermined free running frequency of oscillation, said network including balanced bridge means having a center leg carrying negligible current for providing a biasing voltage for said current source means, said bridge means including two parallel branches having equal currents, at least one of said branches having series diode means having a predetermined change of voltage drop with temperature.

Claim 8

A voltage controlled oscillator responsive to the magnitude of an input control signal for producing an output signal having a frequency related to such magnitude comprising: a semiconductive substrate; a multivibrator having timing capacitor means, the charging and discharging of said capacitor means determining the frequency of oscillation of said output signal of said oscillator; current source means integrated into said substrate, coupled to said capacitor means, and respoNsive to said control signal for determining the frequency of oscillation of said multivibrator; and a temperature dependent network integrated into said substrate for biasing said current source means to provide a predetermined free running frequency of oscillation, said network including balanced bridge means having a center leg carrying negligible current for providing a biasing voltage for said current source means, said bridge means including two parallel branches having equal currents, at least one of said branches having series diode means having a predetermined change of voltage drop with temperature.

Claim 9

In a voltage controlled oscillator responsive to the magnitude of an input control signal for producing an output signal having a frequency related to the magnitude of the input control signal, a body formed of a semiconductor material, a multivibrator having first and second transistors formed in the semiconductor body, load means coupled to the first and second transistors, cross coupling means interconnecting the transistors to provide regenerative feedback between the transistors, said cross coupling means including a timing capacitor, means coupled to the timing capacitor for charging said timing capacitor for determining the frequency of oscillation of the multivibrator, said multivibrator having a frequency deviation from said frequency of oscillation, said means coupled to the timing capacitor for charging the timing capacitor including means for controlling the frequency deviation of the multivibrator independent of the free running frequency of oscillation of the multivibrator, said last named means including a constant current source for supplying a a constant current to said timing capacitor, a variable current source for supplying a variable current to said timing capacitor. said multivibrator having a frequency of oscillation proportional to the sum of said variable and constant current and having a maximum frequency deviation determined by the relative magnitudes of said variable and constant currents, a temperature dependent network coupled to said constant current source, said temperature dependent network including balanced bridge means for providing a biasing voltage for said constant current source.

Claim 10

In a voltage controlled oscillator responsive to the magnitude of an input control signal for producing an output signal having a frequency related to the magnitude of the input control signal, a body formed of a semiconductor material, a multivibrator having first and second transistors formed in the semiconductor body, load means coupled to the first and second transistors, cross coupling means interconnecting the transistors to provide regenerative feedback between the transistors, said cross coupling means including a timing capacitor, means coupled to the timing capacitor for charging said timing capacitor for determining the frequency of oscillation of the multivibrator, said multivibrator having a frequency deviation from said frequency of oscillation, said means coupled to the timing capacitor for charging the timing capacitor including means for controlling the frequency deviation of the multivibrator independent of the free running frequency of oscillation of the multivibrator, said last named means including a constant current source for supplying a a constant current to said timing capacitor, a variable current source for supplying a variable current to said timing capacitor. said multivibrator having a frequency of oscillation proportional to the sum of said variable and constant current and having a maximum frequency deviation determined by the relative magnitudes of said variable and constant currents, a temperature dependent network coupled to said constant current source, said temperature dependent network including balanced bridge means for providing a biasing voltage for said constant current source.

Claim 11

An oscillator as in claim 7 wherein said temperature dependent network has a predetermined temperature coefficient to substantially balance temperature created shifts in said variable current source to thereby provide a substantially zero temperature coefficient for said oscillator.

Claim 12

An oscillator as in claim 7 wherein said variable current source and said constant current source include a current divider network.

Claim 13

An oscillator as in claim 7 wherein said balanced bridge means includes first and second parallel branches, at least one of said branches including series diode means having a predetermined change of voltage drop with temperature.

Claim 14

An oscillator as in claim 10 wherein said branch having said series diode means includes a resistor connected at a junction in series with said diode and wherein the magnitude of said current in said branch is equal to the ratio of the voltage drop across the diode means and the value of said resistor and wherein said balanced bridge includes a center leg connected to the junction between said resistor and said diode means.

Claim 15

An oscillator as in claim 11 wherein the second branch of said balanced bridge includes first and second resistors connected at a junction in series with each other and each having a value equal to the resistor in said branch with said diode means and wherein said center leg is connected to a junction between said first and second resistors.