Patents by Inventor Martin A. Fryer

Martin A. Fryer 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: 6194957
    Abstract: A current mirror comprises reference and output devices (21, 22), and an amplifier (23) for sensing the drain voltages of said devices (21, 22) and applying a control signal to their gates via a normally-closed switch (33). The output current of a circuit (not shown) feeding the reference device (21) may change if the voltage across it becomes too small. The amplifier (23) attempts to force almost identical voltages on the output electrodes of the reference and output devices. If the output voltage (at OUT) of the current mirror approaches an extreme of the output voltage range, the current feeding the reference device may change, and the output current will be incorrect. Also, if at start up the output voltage approaches this extreme, the circuit may “lock up”.
    Type: Grant
    Filed: October 12, 1999
    Date of Patent: February 27, 2001
    Assignee: Lucent Technologies Inc.
    Inventors: Martin A. Fryer, Dominic Charles Royce
  • Patent number: 6107789
    Abstract: A current mirror suitable, for example, for a charge pump circuit comprises a reference device (21), an output device (22), a first amplifier (41), a follower amplifier (42), and switches (31, 32 43, 44). When switches 31 and 43 are closed, the current mirror is enabled and the low output impedance of follower (42) ensures that the gate voltage of output device (22) quickly equals the gate voltage of reference device (21), switching on the output quickly and accurately. When output device (22) is off, switch (44) closes, and the output of the first amplifier (41) bypasses the follower (42) so that the first amplifier (41) and the reference device (21) form a loop, and compensation becomes easier. The amplifiers (41, 42) are separately compensated to make them stable.
    Type: Grant
    Filed: October 12, 1999
    Date of Patent: August 22, 2000
    Assignee: Lucent Technologies Inc.
    Inventors: Martin A. Fryer, Dominic Charles Royce
  • Patent number: 4344045
    Abstract: A phase-locked loop frequency synthesizer with fine tuning comprises a controlled oscillator, a divider for dividing signals provided by the oscillator, a comparator for comparing signals derived from the divider with a reference signal and for providing a control signal for the controlled oscillator, a fine tuning circuit for providing a fine tuning control signal, and a pulse generator responsive to the fine tuning control signals for providing one or more control pulses to control the divider. The divider preferably comprises a two modulus divider for dividing by one of two factors for a period dependent upon the number of control pulses provided by the pulse generator, and for dividing by the other of the two factors for the remainder of the time period. The pulse generator preferably comprises a pulse detection and synchronization circuit and a control pulse generator, each connected to the output of the two modulus divider.
    Type: Grant
    Filed: October 24, 1979
    Date of Patent: August 10, 1982
    Assignee: Plessey Handel und Investments AG
    Inventors: Tapan K. Das, Martin A. Fryer