Patents by Inventor Susumu Fujihara

Susumu Fujihara has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Stabilized power source circuit and IC incorporating the same
    Patent number: 5786970
    Abstract: A stabilized power source circuit is provided with an over current protecting circuit which obtains either a current value or a voltage value corresponding to an output current value of an output transistor as a detected value, compares the detected value with a predetermined constant value and lowers the output current when the detected value exceeds the predetermined constant value. A comparing value generating circuit receives an external signal, generates one of either a predetermined plurality of voltage values or a predetermined plurality of current values in response to the level of the received external signal and transmits the same to the over current protecting circuit as the predetermined constant value.
    Type: Grant
    Filed: March 6, 1996
    Date of Patent: July 28, 1998
    Assignees: Rohm, Co., Ltd., Fujitsu Ten Limited
    Inventors: Yuhji Nao, Susumu Fujihara
  • Constant voltage source circuit
    Patent number: 4983905
    Abstract: A constant voltage source circuit which is provided with an output transistor (Q.sub.1) for outputting a predetermined output voltage (V.sub.0) in accordance with an input voltage (V.sub.IN) and a differential amplifier (A), and is further characterized in that the circuit further comprises a reference voltage control means which monitors variations of the input voltage (V.sub.IN) and outputs a predetermined constant voltage to the differential amplifier (A) as a reference voltage when the input voltage (V.sub.IN) is higher than, a predetermined voltage level, and a voltage varied in accordance with the variation of the input voltage (V.sub.IN) is output therefrom to the differential amplifier (A) as a reference voltage when the input voltage (V.sub.IN) falls below a predetermined voltage level.
    Type: Grant
    Filed: July 5, 1989
    Date of Patent: January 8, 1991
    Assignees: Fujitsu Limited, Fujitsu VLSI Limited, Fujitsu Ten Limited
    Inventors: Yoshiaki Sano, Toshio Hanazawa, Yasuhide Katagase, Katsuyuki Yasukouchi, Takashi Matsumoto, Susumu Fujihara