Hitachi, Ltd.

Toshiyuki Tojo

Naoki Yashiki

Hiroyuki Kida

Nobuo Shibasaki

Seiji Kamada

Masanobu Kawamura

Takeshi Ohkubo

Hiroyuki Matsuura

A variable wave forming circuit is provided which produces signals of various waveforms (e.g., sine, triangular or trapezoidal waves) and various frequencies. A random access memory (memory means) 121 to store wave formation information on waveform is provided. According to the wave formation information stored in the memory means, the updating or keeping of a digital value in an increment/decrement circuit 123 is controlled and the digital value is digital/analog-converted by a digital/analog (D/A) conversion circuit 124, which is controlled by a digital value control means that includes the increment/decrement circuit 123. By writing appropriate wave formation information into the memory means, it is possible to produce signals of desired waveforms.

Method of forming a signal wave from first and second waveform data

Finely adjustable signal wave forming circuit including complementary

Growing community of inventors

Higashimurayama, Japan

Toshiyuki Tojo