Title: Trigonometric wave generation circuit using series expansion
Application Number: 200510072957 Application Date: 2005.05.18
Publication Number: 1707939 Publication Date: 2005.12.14
Approval Pub. Date: Granted Pub. Date:
International Classifi-cation: H03B28/00
Applicant(s) Name: Rohm Co., Ltd. Address:
Inventor(s) Name: Iino Yukinobu;Kurihara Naoki
Attorney & Agent: ma ying shao yali
Abstract:
    The invention relates to a trigonometric genarating circuit which employs progression expanding and the object is to provide a technology for reducing a circuit scale which generates a trigonometric wave. A DTMF signal generating circuit is provided with a frequency designating unit which designates frequencies to form a DTMF signal, a sinusoidal wave computing unit which computes sinusoidal waves by referring to frequencies designated by the frequency designating unit, and a sinusoidal wave synthesizing unit which synthesizes two sinusoidal waves computed by the sinusoidal wave computing unit. The sinusoidal wave computing unit is provided with operators such as an adder-subtracter and a multiplier and generates a sinusoidal wave by determining terms of a Taylor expansion of a sinusoidal function by arithmetic operation.
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