Patents by Inventor Paul Calvin Ferguson

Paul Calvin Ferguson 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: 7262664
    Abstract: Typical amplifier circuits used to implement various type of power amplifiers, including line drivers, are capable of supplying high output currents while maintaining a low standby current. Variation in the manufacturing process, however, can lead to large variations in quiescent current of the amplifier. In particular, transistor mismatch and input offset voltage can cause the quiescent current to be very inconsistent from chip to chip. An amplifier in accordance with the present disclosure uses a transconductance amplifier to stabilize the quiescent current. The transconductance amplifier reduces the gain of the amplifier's input stage for very small signals such as the input offset voltage. The transconductance amplifier saturates for input signals larger than the expected offset voltage, allowing the normal high gain of the input stage to amplify the signal without significant gain reduction.
    Type: Grant
    Filed: June 2, 2005
    Date of Patent: August 28, 2007
    Assignee: Adtran, Inc.
    Inventors: Daniel M. Joffe, Paul Calvin Ferguson