Dynamic body bias Schmitt trigger circuit

Abstract

The invention discloses a dynamic body-bias Schmitt trigger circuit which utilizes a body-bias technique to control the body-area voltages of a first NMOS transistor (10), a first PMOS transistor (11), change the threshold voltages of the first NMOS transistor (10) and the first PMOS transistor (11) and further form the Schmitt trigger circuit with a double-switching threshold value. When an input signal is a lower electric level, under the action of a second NMOS transistor (12), a second PMOS transistor (13), an NMOS body control circuit (14) and a PMOS (15) control circuit, a Schmitt trigger presents a high switching threshold value V+; and similarly, when an input signal is a higher electric level, under the action of the second NMOS transistor (12), the second PMOS transistor (13), the NMOS body control circuit (14) and the PMOS (15) control circuit, the Schmitt trigger presents a low switching threshold value V-.

Description

technical field [0001] The invention relates to a semiconductor integrated circuit, in particular to a Schmitt trigger circuit with double switching thresholds. Background technique [0002] A Schmitt trigger exhibits a hysteresis characteristic in its DC characteristic - there are different switching thresholds for different flipping directions. When the input signal changes from low level to high level, the switching threshold is V+; when the input signal changes from high level to low level, the switching threshold is V—. Schmitt triggers are widely used in digital circuits and analog circuits, especially in anti-noise and waveform shaping, Schmitt triggers play an irreplaceable role. [0003] When the input low-level signal of the Schmitt trigger is coupled with noise, as long as the superposition of the signal level and the noise level does not exceed V+, the output state of the Schmitt trigger will not change; the input high-level signal When there is noise coupled, ...

AI Technical Summary

Problems solved by technology

Since there are two transistors in series on the pull-up and pull-down paths of this Schmitt trigger, it is slower and takes up more chip area

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