Renesas Electronics Corporation

Shunsuke Kizuna

Katsumi Dosaka

Hiroto Utsunomiya

A solid-state image pickup device includes a column ADC realizing higher precision and higher-speed conversion. Converters converts a signal of each pixels output via a corresponding vertical read line to a digital value by sequentially executing first to N-th (N: integer of three or larger) conversion stages. In the first to (N&#x2212;1)th conversion stages, each converter determines a value of upper bits including the most significant bit of a digital value by comparing the voltage at a retention stage with a reference voltage while changing the voltage at a retention node. In the N-th conversion stage, each converter determines a value of remaining bits to the least significant bit by comparing the voltage at the retention node with the reference voltage while continuously changing the voltage at the retention node in a range of the voltage step in the (N&#x2212;1)th conversion stage or a range exceeding the range.

Solid-state image pickup device with plurality of converters

In semiconductor devices according to related art, it is impossible to sufficiently evaluate column ADC interference. According to one embodiment, a semiconductor device includes a plurality of analog/digital conversion circuits that are arranged in a column direction of a pixel array and convert a pixel output signal output from the pixel array for each row into a digital value, and a conversion signal selection circuit that selects one of the pixel output signal and a test signal having a test voltage for each analog/digital conversion circuit according to a test pattern and outputs the selected signal.

Growing community of inventors

Kawasaki, Japan

Shunsuke Kizuna