Patents Represented by Attorney, Agent or Law Firm N. R. H. Black
  • Patent number: 6633494
    Abstract: A charge pump system, including a charge pump and associated distributed clock generation circuitry, is provided for generating high voltages from a low initial voltage in applications such as erasing and programming electrically erasable programmable read only memory (EEPROM) arrays. The charge pump system uses a power supply voltage and a clock and includes a first phase bootstrapping circuit, an inverter, and a second phase bootstrapping circuit, and a two-stage charge pump. The two phase bootstrapping circuits are both responsive to the clock and use a distributed bootstrapping scheme to provide first and second phase clock signals with fixed multiples of the power supply voltage in order to overcome increased effective transistor threshold voltages, increase efficiency, and allow for charge boosting in a limited number of stages. The inverter is connected to the second phase bootstrapping circuit, causing the second phase clock signal to be opposite in phase from the first clock signal.
    Type: Grant
    Filed: October 25, 2001
    Date of Patent: October 14, 2003
    Assignee: Fairchild Semiconductor Corporation
    Inventors: Bob Roohparvar, Kevin Z. Mahouti, Karl Rapp
  • Patent number: 6522559
    Abstract: A charge pump system and associated variable-amplitude clock generation circuitry are provided for generating high voltages from a low initial voltage in applications such as erasing and programming electrically erasable programmable read only memory (EEPROM) arrays. The charge pump system uses a power supply voltage and a clock and includes a first phase bootstrapping circuit, an inverter, and a second phase bootstrapping circuit, and charge pump circuitry. The two phase bootstrapping circuits are both responsive to the clock and provide first and second phase clock signals. The inverter is connected to the second phase bootstrapping circuit, causing the second phase clock signal to be opposite in phase from the first clock signal. The charge pump circuitry is responsive to the power supply voltage and the first and second phase clocks and uses native transistors that have lower threshold voltages.
    Type: Grant
    Filed: October 25, 2001
    Date of Patent: February 18, 2003
    Assignee: Fairchild Semiconductor Corporation
    Inventors: Bob Roohparvar, K. Z. Mahouti, Karl Rapp