Patents Examined by Terry C. Cunningham
  • Patent number: 5220219
    Abstract: An electronically controlled variable gain amplifier is disclosed which provides an output signal proportional to the value of an input signal multiplied by a gain factor, where the gain factor is in turn logarithmically proportional to the value of a gain control signal in the form of a digital word. The amplifier includes a capacitor, a sampler for periodically sampling the value of the input signal and storing the sampled value as a voltage on the capacitor, and circuits for periodically exponentially charging the capacitor after the input signal has been stored thereon for a duration which is directly proportional to the magnitude of the gain control signal. Also included is a circuit for periodically sampling and holding the voltage stored on the capacitor after each periodic charge, where the sampled and held voltage is the amplifier output signal.
    Type: Grant
    Filed: March 10, 1992
    Date of Patent: June 15, 1993
    Assignee: Telerate Systems Incorporated
    Inventor: Andrew C. Barber