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US 2007/0164801 A1Published application
Low hysteresis center offset comparator
AssigneeHoltek Semiconductor Inc.
InventorsYi-Chen Chen, Kevin Hsiao
Life of this patent
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Abstract
Disclosed is a low hysteresis center offset comparator, comprising a first switch device, a differential amplifier, a second switch device, a general comparator, a first inverter and a second inverter. By means of the components, a hysteresis window with the low hysteresis center offset may be formed with respect to the inventive comparator with a width of a half-portion thereof formed equal to that of the other half-portion thereof corresponding to an offset voltage inherent in the differential amplifier.
Claims10
A voltage comparator with a hysteresis, comprising:
- a first switch device;
- a differential amplifier having a non-inverting terminal and an inverting terminal, wherein the non-inverting terminal has an offset voltage and receives one of a non-inverting input signal and an inverting input signal via the first switch device and the inverting terminal receives one of the inverting input signal and the non-inverting input signal via the first switch device to output a differential non-inverting output signal and a differential inverting output signal;
- a second switch device;
- a comparator having a non-inverting terminal and an inverting terminal, wherein the non-inverting terminal receives one of the differential non-inverting output signal and the differential inverting output signal via the second switch device and the inverting terminal receives one of the differential inverting output signal and the non-inverting output signal to output a transitional output signal;
- a first inverter receiving and inverting the transitional output signal to generate a first control signal;
- and
- a second inverter receiving and inverting the first control signal to generate a second control signal as an output signal,
- wherein the first and second control signals jointly control the first and second switch devices so as to make the output signal have a minimum hysteresis center offset.
5 more elements
A current comparator with a hysteresis, comprising:
- a first switch device;
- a differential amplifier having a non-inverting terminal and an inverting terminal, wherein the non-inverting terminal has an offset current and receives one of a non-inverting input signal and an inverting input signal via the first switch device and the inverting terminal receives one of the inverting input signal and the non-inverting input signal via the first switch device to output a differential non-inverting output signal and a differential inverting output signal;
- a second switch device;
- a comparator having a non-inverting terminal and an inverting terminal,
- wherein the non-inverting terminal receives one of the differential non-inverting output signal and the differential inverting output signal via the second switch device and the inverting terminal receives one of the differential inverting output signal and the non-inverting output signal to output a transitional output signal;
- a first inverter receiving and inverting the transitional output signal to generate a first control signal;
- and
- a second inverter receiving and inverting the first control signal to generate a second control signal as an output signal,
- wherein the first and second control signals jointly control the first and second switch devices so as to make the output signal have a minimum hysteresis center offset.
6 more elements
Dependencies are inferred from the claim text.