JPH01218214A - Phase locked oscillating circuit - Google Patents

Abstract

PURPOSE:To simplify a constitution and to freely execute the individual adjustment of respective coefficients by impressing the output of a proportionate amplifier to one edge of a variable capacity diode and impressing the output of an integration circuit to other edge of a variable capacity diode. CONSTITUTION:The title circuit is equipped with a voltage controlled oscillator(VCO) 8 to control an oscillation frequency by the voltage impressed to a variable capacity diode(VCD) 7. In such a constitution, the phase of an oscillation output OUT of the VCO 8 and an external input signal Si is compared with a phase comparator 2, the output is proportionately amplified by a proportionate amplifier 3 and impressed through a resistor 9 to one edge of the VCD 7. The output of the phase comparator 2 is also inputted and integrated to an integration circuit 4, impressed through a resistor 10 to other edge of the VCD 7 and thus, the transmission phase of the VCO 8 is synchronized to the phase of the external input signal Si. Consequently, by respective outputs of the proportionate amplifier 3 and the integration circuit 4, the inter-terminal voltage of the VCD 7 is directly specified, an adding circuit 5 is made unnecessary and the individual adjustment of respective coefficients can be freely executed by resistors 9 and 10.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a phase synchronized oscillation system in which a voltage controlled oscillator (hereinafter referred to as VCO) '1 is controlled through a proportional amplifier and an integrating circuit to obtain an oscillation output with zero phase error. There are things related to circuits.

[Conventional technology]

Such oscillation circuits are particularly used in devices in which a phase error between the oscillation output and an external input signal is a problem;
As shown in the block diagram of Fig. 2, the phase of the reference external input signal S1 and the oscillation output OUT of the VCOl is compared by the phase north terminal device 2, and this output is proportionally amplified by the proportional amplifier 3, and the integrator circuit 4, these outputs are added by an adder 5, and then applied to the control terminal of vcot via a resistor 6, thereby synchronizing the oscillation output phase of vcot with the phase of external input signal S1. ing.

[Problem to be solved by the invention]

However, in the above configuration, the adder 5 is required, and the proportional coefficient of the proportional amplifier 3 and the integral coefficient of the integral circuit 4 must be adjusted individually, and the circuit configuration becomes complicated accordingly. It is unsuitable for mass production and has drawbacks such as being expensive.

[Means for Solving Problem 11] In order to solve the above-mentioned problem, the present invention is constituted by a hand RK.

That is, a VCO whose oscillation frequency is controlled by a voltage applied to a variable capacitance diode (hereinafter referred to as van), a phase comparator that compares the phase of the output of this VCO and an external input signal, and a phase comparator that compares the output of this VCO proportionally. The proportional amplifier amplifies and applies it to one end of the VCD, and the output of the phase comparator is integrated and the VC
and an integrating circuit that applies voltage to the other end of D.

[Effect]

Therefore, the VCO is directly controlled by the outputs of the proportional amplifier and the integrating circuit, eliminating the need for an adder.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to the boot diagram of FIG. 1 showing an embodiment.

In the figure, a VCOA whose oscillation frequency is controlled by the voltage applied to the VCD 7 is provided, and the phase of the oscillation output OUT of this VCOA and the external input signal Sl is compared by a phase comparator 2, and this output is connected to a proportional amplifier. 3, and then applied to one end of the VCD 7 through a resistor 9. At the same time, the output of the 1-phase comparator 2 is integrated by an integrating circuit 4, and applied to the other end of the VCD 7 through a resistor 10t. This allows the oscillation phase of vcoa to be adjusted to the external input signal S1.
It is synchronized with the phase of

Therefore, each output of the proportional amplifier 3 and the integrating circuit 4 directly determines the voltage between the terminals of the VCD 7, and the adding circuit 5
is not necessary, and each coefficient can be adjusted individually using the resistors 9 and 10, so that the purpose can be achieved with a simple configuration.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the output of the proportional amplifier is applied to one end of the VCD, and the output of the integrating circuit is applied to the other end of the VCD. Each coefficient can be adjusted individually, and a remarkable effect can be obtained in synchronous oscillation when zero phase error is required.

[Brief explanation of the drawing]

FIG. 81 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional example. 2 @... Phase comparator, 3... Fist/proportional amplifier, 4 Fist/
... Integrating circuit, 7... Variable capacitance diode, 8...
...Voltage controlled oscillator, sl ...External input signal, 0
υT...Oscillation output.

Claims (1)

[Claims] a voltage controlled oscillator whose oscillation frequency is controlled by a voltage applied to a variable capacitance diode; a phase comparator that compares the phase of the output of the oscillator with an external input signal; and a phase comparator that proportionally amplifies the output of the comparator. A phase-locked oscillator circuit comprising: a proportional amplifier that applies voltage to one end of a variable capacitance diode; and an integration circuit that integrates the output of the comparator and applies it to the other end of the variable capacitance diode.