Patents Assigned to Wolfson Microelectronics, Ltd.
  • Patent number: 6831507
    Abstract: A transconductance difference amplifier (300) is described, for providing an output current dependent upon a difference between a first input voltage (302) and a second input voltage (304). The difference amplifier comprises an input sampling capacitor (306) having two conductors; a transconductance amplifier (312) having an input (318) coupled to a first conductor of said input sampling capacitor and a current output (314) for generating said output current; and an input switch (308, 310) for selectively coupling a second conductor of said input sampling capacitor to a first input of said difference amplifier for receiving said first input voltage and to a second input of said difference amplifier for receiving said second input voltage.
    Type: Grant
    Filed: September 20, 2002
    Date of Patent: December 14, 2004
    Assignee: Wolfson Microelectronics, Ltd.
    Inventor: Edward M. Granville
  • Patent number: 6799889
    Abstract: Circuits and methods for generating a temperature dependent signal are described involving: generating a thermal voltage referenced positive temperature coefficient signal using a pair of transistors operating at different current densities; generating a transistor voltage referenced negative temperature coefficient signal using a transistor voltage of one of said pair of transistors; and subtracting one of said positive and negative temperature coefficient signals from the other of said signals to generate said temperature dependent signal, whereby the temperature dependence of said temperature dependent signal is greater than either of said subtracted signals.
    Type: Grant
    Filed: October 7, 2002
    Date of Patent: October 5, 2004
    Assignee: Wolfson Microelectronics, Ltd.
    Inventor: John L. Pennock