Patents by Inventor Melvin Chan

Melvin Chan 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: 5315174
    Abstract: An output buffer circuit is disclosed that minimizes ground bounce problems. The buffer circuit provides for an output pull-down pre-driver circuit that can be controlled by a programmable signal to minimize the ground bounce. By placing a strong and weak transistor on the gate of the output driver transistor and providing control circuitry for disabling the stronger transistor appropriately, an output signal is provided that can be driven quickly or slowly to its active level. By disabling the stronger transistor, ground bounce problems associated with high to low transitions of output drive transistor are significantly reduced.
    Type: Grant
    Filed: August 13, 1992
    Date of Patent: May 24, 1994
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Herman M. Chang, Melvin Chan
  • Patent number: 5226051
    Abstract: Method and apparatus for stabilization of pulse energies produced by a continuously pumped, Q-switched, solid-state or gas laser, through control of the optical power delivered by an optical pump to the laser, in order to limit the energy emitted in any single laser pulse as a result of Q-switching. The laser pump is driven at full strength for a selected initial refresh time t.sub.r. If a Q-switch trigger signal is received by the laser before the elapsed time .DELTA.t has reached the refresh time t.sub.r, the laser emits a pulse with the reduced energy stored in the laser at that time. If the elapsed time reaches or exceeds the refresh time t.sub.r, the optical pump power subsequently delivered to the laser is reduced to a lower level, which may be time-dependent, that is sufficient to maintain the net energy stored in the laser at a predetermined value so that the energy in a subsequently emitted laser pulse does not exceed a selected limit.
    Type: Grant
    Filed: June 4, 1991
    Date of Patent: July 6, 1993
    Assignee: Lightwave Electronics
    Inventors: Melvin Chan, Henry G. Plaessman, Frank Adams, William M. Grossman
  • Patent number: 4633413
    Abstract: Digital dilution apparatus is disclosed which performs multiple processing functions such as pipetting, diluting, titrations and the like under microprocessor control. The apparatus is responsive to operator-entered processing requests and performs complex and accurate processing functions. The disclosed apparatus is quite simple and easy to operate and does not require a highly skilled operator.
    Type: Grant
    Filed: July 28, 1983
    Date of Patent: December 30, 1986
    Assignee: Cavro Scientific Instruments
    Inventors: Robert Caveney, Dana Gilliam, Melvin Chan, Michael Bailey