Patents by Inventor Tomoaki Kuramasu

Tomoaki Kuramasu 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).

  • Patent number: 9479172
    Abstract: The differential output buffer comprises the differential output circuit, and the bias voltage generation circuit that is the replica circuit of the differential output circuit. The bias voltage generation circuit generates, by the operational amplifier, the bias voltage for controlling currents respectively flowing in the first current source of the differential output buffer and the second current source of the bias voltage generation circuit such that the voltage of the third internal node between the third internal and external resistors and the third switch of the bias voltage generation circuit becomes equal to the reference voltage equal to the voltage of the first internal node when the first switch of the differential output buffer is in an ON state or equal to the voltage of the second internal node when the second switch of the differential output buffer is in an ON state.
    Type: Grant
    Filed: January 21, 2016
    Date of Patent: October 25, 2016
    Assignee: MegaChips Corporation
    Inventor: Tomoaki Kuramasu
  • Publication number: 20160218715
    Abstract: The differential output buffer comprises the differential output circuit, and the bias voltage generation circuit that is the replica circuit of the differential output circuit. The bias voltage generation circuit generates, by the operational amplifier, the bias voltage for controlling currents respectively flowing in the first current source of the differential output buffer and the second current source of the bias voltage generation circuit such that the voltage of the third internal node between the third internal and external resistors and the third switch of the bias voltage generation circuit becomes equal to the reference voltage equal to the voltage of the first internal node when the first switch of the differential output buffer is in an ON state or equal to the voltage of the second internal node when the second switch of the differential output buffer is in an ON state.
    Type: Application
    Filed: January 21, 2016
    Publication date: July 28, 2016
    Applicant: MegaChips Corporation
    Inventor: Tomoaki Kuramasu
  • Patent number: 7420395
    Abstract: An output buffer circuit, which minimizes or prevents output delay of output signal and degradation of slew rate while suppressing overshoot and undershoot, is provided. In a first time period when an input signal to a gate of an N-channel output transistor changes from ‘L’ level to ‘H’ level, the gate is connected to an output terminal through a capacitor element so that the overshoot is suppressed. In addition, the output buffer circuit stores negligible electrical charge in the capacitor element prior to the first time period, which results in minimal delay in outputting a buffered signal and degradation of slew rate while suppressing undershoot when the input signal changes from ‘H’ level to ‘L’ level in the first time period.
    Type: Grant
    Filed: March 27, 2007
    Date of Patent: September 2, 2008
    Assignee: Kawasaki Microelectronics, Inc.
    Inventor: Tomoaki Kuramasu
  • Publication number: 20070247193
    Abstract: An output buffer circuit, which minimizes or prevents output delay of output signal and degradation of slew rate while suppressing overshoot and undershoot, is provided. In a first time period when an input signal to a gate of an N-channel output transistor changes from ‘L’ level to ‘H’ level, the gate is connected to an output terminal through a capacitor element so that the overshoot is suppressed. In addition, the output buffer circuit stores negligible electrical charge in the capacitor element prior to the first time period, which results in minimal delay in outputting a buffered signal and degradation of slew rate while suppressing undershoot when the input signal changes from ‘H’ level to ‘L’ level in the first time period.
    Type: Application
    Filed: March 27, 2007
    Publication date: October 25, 2007
    Applicant: KAWASAKI MICROELECTRONICS, INC.
    Inventor: Tomoaki Kuramasu