JPH07221543A - Cyclic on-off controlled oscillator - Google Patents

Abstract

PURPOSE:To reduce an oscillation output start-up time and to prevent adverse effect such as leakage of oscillation to a peripheral circuit by applying on/off control to the operation of an active element cyclicaly. CONSTITUTION:Since an oscillated output rises in a smaller delay time than an oscillation output rising delay time being a time from OFF to ON simply when the oscillated output is subject to on/off control by having only to apply on/off control to a power supply for an active element 1 cyclicaly, the oscillation output rising time is reduced. Furthermore, the oscillation is controlled completely stopped when the active element 1 is turned off. When the oscillator is used for a TDMA system radio communication whose transmission and reception frequencies are identical, since the oscillation is completely stopped in a reception time slot of a concerned station and the oscillation starts up in a transmission time slot, the internal interference between transmission and reception is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to oscillation control of a self-excited oscillator, and more particularly to a cyclic on / off controlled oscillator.

[0002]

2. Description of the Related Art Normally, an oscillator is composed of an active element 1 and a feedback circuit 2 as shown in FIG. 1, but when a high Q resonator (such as a crystal oscillator) is used for the feedback circuit 2, It is known that there is a delay time determined by the bandwidth of the feedback circuit 2 even when the active element 1 is turned on, and therefore it takes time for the oscillation output to rise. Therefore, conventionally, in order to speed up the rise of the oscillation output at the time of turning on and off, a method is used in which the active element 1 is always turned on and oscillated, and the output is turned on and off by a switch.

[0003]

However, in the above-mentioned conventional example, although the rise of the oscillation output can be speeded up, the oscillation operation is performed even when the switch is off, so that leakage from the switch and mounting of components are not caused. There is a problem that radiation or the like adversely affects other peripheral circuits.

[0004]

The oscillator of the present invention is an active element of a self-excited oscillator composed of a feedback circuit 2 using a resonator for determining an oscillation frequency and an active element 1 in order to solve the above problems. It is characterized in that the operation No. 1 is cyclically turned on and off.

[0005]

[Operation] By cyclically controlling the operation of the active element 1 as described above, the rise time of the oscillation output can be shortened.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory diagram of a self-excited oscillator which is the object of the present invention. In the embodiment of the present invention, the power supply of the active element 1 is cyclically controlled to be turned on and off in the self-excited oscillator including the feedback circuit 2 and the active element 1 which use the resonator for determining the oscillation frequency. When the oscillation output is turned on / off by turning on / off the power supply of the active element 1, by simply turning the power supply from OFF to ON as shown in FIG. 2A, the power supply is turned OFF as shown in FIG. 2B. The oscillation output rises after a delay of T ₁ from the time when it is turned on, and it takes time for the oscillation output to rise. However, by turning the power supply on and off cyclically as shown in FIG.
As shown in (d), the oscillation output rises after T ₂ time <T ₁ hours from the time when the power supply is switched from off to on, and the rise time of the oscillation output can be shortened. In the present invention, the operation of the active element 1 may be cyclically turned on / off by switching the on / off control signal cyclically.

In this embodiment, it is possible to control the oscillator such that the oscillation output rises quickly and the oscillation is completely stopped when the active element is turned off. For example, TDM with the same transmission / reception frequency
In the wireless communication of the A system, by using the present invention as an oscillator for transmission, the oscillation can be completely stopped in the receiving time slot of the local station, and the oscillation can be set to the rising state in the transmitting time slot. And the internal interference of reception can be prevented.

[0008]

As described above, according to the present invention, the operation of the active element 1 of the self-excited oscillator constituted by the feedback circuit 2 using the resonator for determining the oscillation frequency and the active element 1 is cyclically performed. Since it is characterized by turning on and off,
Not only the rise time of the oscillation output can be shortened and the oscillation can be completely stopped when the active element is turned off, but also adverse effects due to oscillation leakage to other peripheral circuits can be prevented.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a self-excited oscillator that is a target of the present invention.

2 (a) to 2 (d) are explanatory views of the operation of the oscillator of the present invention.

[Explanation of symbols]

 1 Active element 2 Feedback circuit

Claims (1)

[Claims] 1. In a self-excited oscillator including a feedback circuit using a resonator for determining an oscillation frequency and an active element, the operation of the active element is cyclically on / off controlled. Controlled oscillator.