Mitsumi Electric Company Ltd.

Tomoki Segawa

Koji Yano

Fumihiro Inoue

A successive approximation AD converter includes a DA converter that converts a higher conversion data greater than an approximate value into an analog higher converted voltage and converts a lower conversion data less than the approximate value into an analog lower converted voltage; a sample-and-hold circuit that samples and holds voltage differences between an input voltage and each of the higher converted voltage and the lower converted voltage; a comparator that outputs a first comparison result indicating whether the input voltage is greater or less than the higher converted voltage and a second comparison result indicating whether the input voltage is greater or less than the lower converted voltage; and an operation unit that changes the approximate value based on the first comparison result and the second comparison result, and changes a next higher conversion data and a next lower conversion data based on the changed approximate value.

Successive approximation AD converter and successive approximation AD conversion method

In a state of a first semiconductor integrated circuit device on which a first semiconductor integrated circuit board including a first mask ROM and a programmable ROM are mounted, an ultimate program determined by using the programmable ROM is stored in a second ROM of a second semiconductor integrated circuit board which is substantially similar in structure to the first semiconductor integrated circuit board, thereby manufacturing a second semiconductor integrated circuit device as an ultimate product.

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Hokkaido, Japan

Tomoki Segawa