Liquid-level gauge driver circuit
First Claim
1. An integrated circuit embodied in a single semiconductor chip for providing a liquid level gauge display driving signal to a liquid level gauge, the integrated circuit receiving a liquid level signal from a liquid level sensor unit, the integrated circuit comprising:
- a clock signal circuit for providing a clock signal at a clock frequency;
a digital logic circuit coupled to the clock signal circuit for converting the clock signal into a plurality of internal clock signals having different frequencies;
a comparing circuit coupled to said digital logic circuit for generating the liquid level gauge display driving signal and for comparing the liquid level signal with the liquid level gauge display driving signal;
a current switch circuit coupled to the comparing circuit for driving a reference current into the liquid level sensor unit, the reference current being converted into the liquid level signal having a voltage value proportional to a liquid level measured by the liquid level sensor unit, the voltage value of the liquid level signal then being fed into the comparing circuit; and
a gauge driver circuit coupled to said comparing circuit for driving the liquid level gauge.
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Accused Products
Abstract
A liquid level sensor unit outputs a voltage value, which corresponds to a measured liquid level, to an anti-slosh circuit that provides a fast timing rate during the initial condition of the circuit and a slow timing rate during the normal operation of the circuit. The anti-slosh circuit further includes a low liquid level warning circuit and a power-on-reset circuit. The system timing rate can be externally controlled by connecting an RC circuit to the improved anti-slosh circuit. A customer defined reference level for low liquid warning is also possible. The entire circuit is included on a single, monolithic integrated circuit. An input pin receives the signal from the fuel tank. An output pin drives a liquid level gauge.
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Citations
10 Claims
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1. An integrated circuit embodied in a single semiconductor chip for providing a liquid level gauge display driving signal to a liquid level gauge, the integrated circuit receiving a liquid level signal from a liquid level sensor unit, the integrated circuit comprising:
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a clock signal circuit for providing a clock signal at a clock frequency; a digital logic circuit coupled to the clock signal circuit for converting the clock signal into a plurality of internal clock signals having different frequencies; a comparing circuit coupled to said digital logic circuit for generating the liquid level gauge display driving signal and for comparing the liquid level signal with the liquid level gauge display driving signal; a current switch circuit coupled to the comparing circuit for driving a reference current into the liquid level sensor unit, the reference current being converted into the liquid level signal having a voltage value proportional to a liquid level measured by the liquid level sensor unit, the voltage value of the liquid level signal then being fed into the comparing circuit; and a gauge driver circuit coupled to said comparing circuit for driving the liquid level gauge. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An integrated circuit embodied in a single semiconductor chip for providing a liquid level gauge display driving signal to a liquid level gauge, the integrated receiving a liquid level signal from a liquid level sensor unit, the integrated circuit comprising:
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a clock signal circuit for providing a clock signal at a clock frequency; a digital logic circuit coupled to the clock signal circuit for converting the clock signal into a plurality of internal clock signals having different frequencies; a comparing circuit coupled to said digital logic circuit for generating the liquid level gauge display driving signal and for comparing the liquid level signal with the liquid level gauge display driving signal; a current reference circuit connected to a power supply wherein the current reference circuit provides a reference current to the liquid level sensor unit for measuring a liquid level having a corresponding voltage value from the liquid level sensor unit; a current multiplying circuit wherein the current multiplying circuit offsets the reference current by a factor of the power supply'"'"'s voltage value such that a mere fluctuation of the power supply'"'"'s voltage value would not shift position, or change value, of an indicator of the liquid level gauge; and a gauge driver circuit coupled to said comparing circuit for driving the liquid level gauge.
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Specification