Patents Assigned to National Semiconductor Corp. Inc.
  • Patent number: 6452414
    Abstract: A power-on sense circuit accurately senses a power-on condition when a power supply voltage exceeds a desired trigger voltage level. The power-on sense circuit includes a voltage-to-current converter circuit and a beta-multiplier reference circuit. The voltage-to-current converter circuit and the beta-multiplier reference circuit generate currents that relate to the power supply voltage. By sensing a balanced current operating condition with the beta-multiplier reference circuit, the power-on sense circuit determines when a desired trigger voltage has been achieved. The trigger voltage level has a zero temperature coefficient at median operating temperatures, and has a slightly downward curvature shape without the need for high-current resistor-dividers or bandgap circuits. The power-on sense circuit may be adapted for use as a power-on reset signal. By adding an amplifier stage to the outputs signal, the power-on sense circuit may also be used as an analog reference voltage generator.
    Type: Grant
    Filed: November 21, 2000
    Date of Patent: September 17, 2002
    Assignee: National Semiconductor Corp. Inc.
    Inventor: Perry Scott Lorenz