| 摘要 |
A Schmitt trigger circuit that has a separate HI bias circuit, a separate LO bias circuit, and a trigger circuit that includes HI and LO sections that respectively match the circuitry in the HI and LO bias circuits. HI and LO threshold signals are applied to locations in the HI and LO bias circuits that correspond to an input terminal for the trigger circuit, while particular nodes in the bias circuits are connected to corresponding locations in the trigger circuit to set up matching signal levels when the trigger input equals either the HI or the LO threshold levels. The bias circuits include negative feedback paths which inhibit errors due to process, temperature or supply voltage variations, while switching set points are applied to the bias circuits and reflected to the trigger circuit to set the output voltage at a desired level that corresponds to an intermediate point in the switching transition. The circuit can thus be set to be at the middle of a switching transition, with a maximum rate of output voltage change, at the threshold levels.
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