Fujitsu Corporation

Fujifacom Corporation

Ffc Limited

Takeshi Kikuchi

Shunsuke Fueki

Andrzej Radecki

Takayuki Nagasawa

Toshiyuki Teramoto

Hiroshi Okubo

Shinji Yajima

Katsuyoshi Shimada

Masayoshi Isobe

A power supply circuit for supplying power to a load includes an antenna which receives electric power, a rectifier coupled to the antenna and configured to convert an alternating voltage supplied from the antenna into a direct-current voltage, a voltage step-down circuit which steps down the direct-current voltage to generate an output voltage for provision to the load, a regulator which controls a resistance connected between the output voltage and a ground voltage in parallel with the load, thereby controlling a voltage level of the output voltage.

Power supply circuit that is stable against sudden load change

A digital filter has a cut-off frequency which can be varied by a simple control circuit. The digital filter includes a tap coefficient setting section and a convolution calculation section. The convolution calculation section is constructed so as to repetitively perform the processing of first performing repetitive convolution calculation wherein a same convolution calculation operation is performed once or successively by a plurality of times using same tap coefficients or same input data and then varying the tap coefficient or the input data to allow the repetitive convolution calculation to be repeated subsequently. The digital filter can be applied to an oversampling analog to digital converter.

Digital filter and oversampling analog to digital converter employing

Growing community of inventors

Hino, Japan

Takeshi Kikuchi