Patents by Inventor Raymond J. Speer

Raymond J. Speer 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: 5075677
    Abstract: In a voltage-switching digital-to-analog converter, each bit is switched by a switching circuit which uses a p-channel MOSFET as a V.sub.ref switch and an n-channel MOSFET as an Agnd switch, with a control circuit for controlling the signal applied to the gate of one of the devices (e.g., the n-channel device) to cause its "ON" resistance to match the "ON" resistance of the other device (e.g., the p-channel device). The control circuit includes reference n-channel and p-channel devices. A control signal is developed to drive the reference n-channel device to a condition wherein its drain current and drain-source voltage match those of the reference p-channel device, thereby causing their R.sub.ON s to match. The drive signal is taken as the output of the control means and is used to power the driver for the n-channel Agnd switches.
    Type: Grant
    Filed: July 27, 1989
    Date of Patent: December 24, 1991
    Assignee: Analog Devices, Inc.
    Inventors: Richard A. Meaney, Raymond J. Speer