JPS6016705A - Sinusoidal wave generator - Google Patents

Abstract

PURPOSE:To obtain easily a sinusoidal wave stable to an optionally set frequency by using a clock control filter as a filter for waveform shaping so as to have only to use one common filter circuit to an optional frequency. CONSTITUTION:A signal generated at a reference signal generating circuit 11 is applied to a variable frequency division circuit 12. The frequency dividing ratio of the variable frequency dividing circuit 12 is set by a signal applied to a frequency setting terminal 15 and a signal having a frequency being, e.g., n-times a desired sinusoidal wave frequency is obtained at the output. this signal having n-times frequency becomes a signal having the desired frequency through, e.g., a 1/n frequency dividing circuit 13 and is inputted to a switched capacitor filter 14. On the other hand, an output of the variable frequency dividing circuit 12 acts like a clock signal of the filter 14 and its cut-off characteristic is controlled to be optimized always to an optional frequency set by a frequency setting terminal 16, allowing to obtain a sinusoidal wave having a prescribed characteristic at the output terminal 16.

Description

【発明の詳細な説明】 本発明は正弦波発生装置に関するもので、設定された任
意の周波数に対して安定な正弦波が容易に得られるよう
にしたものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sine wave generator that can easily generate a stable sine wave at any set frequency.

従来この種の装置は、例えば第１図に示す様に基準信号
発生回路１、周波数設定端子６からの信号で制御される
可変分周回路２、ろ波器切替回路ア、および固定遮断特
性のｐ波器群８、混合回路９等で構成され出力端子６か
ら正弦波を得るようにしている。Conventionally, this type of device includes, for example, a reference signal generation circuit 1, a variable frequency divider circuit 2 controlled by a signal from a frequency setting terminal 6, a filter switching circuit A, and a fixed cutoff characteristic, as shown in FIG. It is composed of a p-wave generator group 8, a mixing circuit 9, etc., and is configured to obtain a sine wave from the output terminal 6.

この装置において、出力端子６に周波数設定端子６で設
定される任意の周波数の正弦波を得るためにはその出力
周波数の範囲・種類が増大するに従ってｐ波器群８を構
成するｐ波器の数を増加させなければならない欠点があ
った。In this device, in order to obtain a sine wave of an arbitrary frequency set at the frequency setting terminal 6 at the output terminal 6, as the range and type of output frequency increases, There was a drawback that the number had to be increased.

本発明はそのような欠点を除去するもので、以下にその
実施例とともに説明する。第２図において、１１は基準
信号の発生回路、１２は端子１５に加わる周波数設定信
号により分周比の制御される可変分周回路、１３は分周
比の固定された分周回路、１４は可変分周回路１２の出
力でＰ波特性が制御されるスイノチドキャパシタフィル
タ（クロック制御ｐ波器）である。The present invention eliminates such drawbacks and will be described below with examples thereof. In FIG. 2, 11 is a reference signal generation circuit, 12 is a variable frequency divider circuit whose frequency division ratio is controlled by the frequency setting signal applied to the terminal 15, 13 is a frequency divider circuit with a fixed frequency division ratio, and 14 is a frequency divider circuit whose frequency division ratio is controlled by the frequency setting signal applied to the terminal 15. This is a suinotide capacitor filter (clock-controlled p-wave filter) whose P-wave characteristics are controlled by the output of the variable frequency divider circuit 12.

次にこの実施例の動作について説明する。Next, the operation of this embodiment will be explained.

基準信号発生回路１１で発生した信号は可変分周回路１
２に加わる。この可変分周回路１２の分周比は周波数設
定端子１６に加わる信号により設定され、その出力には
希望する正弦波周波数のたとえばｎ倍（ｎ〉１の整数）
の周波数の信号を得る。このｎ倍の信号はたとえば１／
ｎの分周回路１３を通って希望する周波数の信号となり
スイッチドキャバ７タフィルタ１４に入力される。The signal generated by the reference signal generation circuit 11 is sent to the variable frequency divider circuit 1.
Join 2. The frequency division ratio of this variable frequency divider circuit 12 is set by a signal applied to the frequency setting terminal 16, and its output is set to, for example, n times the desired sine wave frequency (an integer where n>1).
Obtain a signal with a frequency of . This n-times signal is, for example, 1/
The signal passes through the n frequency divider circuit 13, becomes a signal of a desired frequency, and is input to the switched cavator filter 14.

一方１可変分周回路１２の出力はスイッチト゛キャパシ
タフィルタ１４のクロ、ツク信号としても働き、その遮
断特性は周波数設定端子１６で設定された任意の周波数
に対して常に最適になる様に制御されることになり出力
端子１６には一定の特性の正弦波を得ることができる。On the other hand, the output of the 1 variable frequency divider circuit 12 also functions as a clock signal for the switched capacitor filter 14, and its cutoff characteristics are always controlled to be optimal for any frequency set at the frequency setting terminal 16. Therefore, a sine wave with constant characteristics can be obtained at the output terminal 16.

上記実施例より明らかなように、波形整形用ろ波器とし
てクロック制御ろ波器を使用することにより、任意の周
波数に対して、波形整形用ろ波器は共通のものが１回路
ですむため構成の簡単化ができる。また、遮断特性が入
力周波数に対応して変化するため、任意の周波数に対し
て一定の特性（レベル・歪等）の正弦波が得られる等の
利点がある。また、集積回路化が容易である。As is clear from the above example, by using a clock-controlled filter as a waveform shaping filter, only one common waveform shaping filter is required for any frequency. The configuration can be simplified. Furthermore, since the cut-off characteristic changes depending on the input frequency, there are advantages such as a sine wave having constant characteristics (level, distortion, etc.) for any frequency. In addition, it is easy to integrate into an integrated circuit.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は従来の正弦波発生装置のブロック図、第２図は
本発明の一実施例における正弦波発生装置のブロック図
でおる。 １３・・・・・・分周回路、１４・・・・・スイノナド
キャパシタフィルタ。FIG. 1 is a block diagram of a conventional sine wave generator, and FIG. 2 is a block diagram of a sine wave generator according to an embodiment of the present invention. 13... Frequency divider circuit, 14... Suinonado capacitor filter.

Claims (1)

【特許請求の範囲】[Claims] 出力正弦波と周波数の等して方形又は擬似正弦波を発生
する信号発生回路、上記信号発生回路の出力信号が入力
として加わる一方その入力周波数に対応して遮断特性の
変化するクロック制御Ｆ波器を設けたことを特徴とする
正弦波発生装置。A signal generating circuit that generates a square or pseudo sine wave with the same frequency as the output sine wave, and a clock-controlled F-wave device that receives the output signal of the signal generating circuit as an input and whose cutoff characteristics change in accordance with the input frequency. A sine wave generator characterized by being provided with.