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US 5,327,020 AGranted
Schmitt trigger input buffer circuit
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorNobuyuki Ikeda
Life of this patent
Estimating the term…
Abstract
A Schmitt trigger input buffer circuit includes two inverting gates with different threshold voltages, which receive an input signal, a dual-input-AND pair and dual-input-NOR composite gate, and another inverting gate. Two of the inputs of the composite gate receive the outputs from the two inverting gates. The output signal of the composite gate and its inverted version are fed back respectively to the remaining two inputs of the composite gate.
Claims22
A Schmitt trigger input buffer circuit, comprising:
- an input terminal;
- a first input gate having a first output;
- a second input gate having a second output;
- said first and second input gates being connected in parallel to said input terminal and having different operating threshold voltages;
- a dual-input-AND pair and dual-input-NOR composite gate having a first set of inputs connected respectively to said first and second output of said first and second input gate, having a second set of inputs for independently enabling said composite gate to be responsive to a selected one of said first set of inputs, and having an output;
- an output terminal connected to said output of said composite gate;
- and
- a circuit for feeding back said output signal of said composite gate to said second set of inputs of said composite gate.
5 more elements
A Schmitt trigger input buffer circuit, comprising:
- an input terminal;
- a first input gate having a first output;
- a second input gate having a second output;
- said first and second input gates being connected in parallel to said input terminal and having different operating threshold voltages;
- a dual-input-AND pair and dual-input-NOR composite gate having a first set of inputs connected respectively to said first and second output of said first and second input gate, having a second set of inputs for independently enabling said composite gate to be responsive to a selected one of said first set of inputs, and having an output;
- an output terminal connected to said output of said composite gate;
- and
- one of said first and second output signals of said first and second input gates that are applied to said first set of inputs of said composite gate is selected to define said output of said composite gate by a feedback signal from said output of said composite gate.
5 more elements
A Schmitt trigger input buffer circuit, comprising:
- an input terminal;
- a first input gate having a first output;
- a second input gate having a second output;
- said first and second input gates being connected in parallel to said input terminal and having different operating threshold voltages;
- a dual-input-AND pair and dual-input-NOR composite gate having a first set of inputs connected respectively to said first and second output of said first and second input gate, having a second set of inputs for independently enabling said composite gate to be responsive to a selected one of said first set of inputs, and having an output;
- means for feeding back said output signal and its inverted version from said composite gate to said second set of inputs;
- and
- an output terminal connected to said output of said composite gate.
5 more elements
A Schmitt trigger input buffer circuit, comprising:
- an input terminal;
- a first input gate having a first output;
- a second input gate having a second output;
- said first and second input gates being connected in parallel to said input terminal and having different operating threshold voltages;
- a dual-input-AND pair and dual-input-NOR composite gate having a first set of inputs connected respectively to said first and second output of said first and second input gate, having a second set of inputs for independently enabling said composite gate to be responsive to a selected one of said first set of inputs, and having an output;
- means for connecting said output of said composite gate to a one of said second set of inputs;
- means for connecting said output of said composite gate to another one of said second set of inputs via an inverting gate;
- and
- an output terminal connected to said output of said composite gate.
6 more elements
A Schmitt trigger comprising:
- an input circuit having a first and a second output, said first and second output each being responsive at a different threshold of an input signal applied to said input circuit;
- a logic circuit having a first and second set of inputs wherein a first input of each of said first and second set of inputs enables said logic circuit to be responsive to a signal applied to a selected second input of said first and second set of inputs;
- said second input of each of said first and second set of inputs respectively connected to said first and second outputs of said input circuit;
- said logic circuit having an output responsive to said selected second input;
- feedback means, applied to said first inputs, for enabling said logic circuit, to be responsive to an output of said first and second outputs that is last to respond to a transition of said input signal applied to said input circuit;
- and
- said feedback means having said output of said logic circuit as an input.
4 more elements
Dependencies are inferred from the claim text.