Schmitt trigger you understand ~ how to use the op-amp constitute a simple Schmitt trigger?




A,
Schmitt trigger has two stable states, but unlike general trigger, Schmitt trigger adopts potential triggering method, its state by the input signal is potential to maintain; For increasing diminishing negative and positive two different input signal in the direction of change, Schmitt trigger has different threshold voltage,



This trigger because of the output voltage and input voltage is an oblong to linear, so called the Schmitt trigger, seen from the curve, when the input Vi=0 output VO=1, when the input voltage from zero to ascend to VDD> 2/3, the VO to flip to 0, when the input voltage falls, from their highest levels to drop & lt; VDD/3, the VO to flip into 1, so between the output voltage and input voltage is a linear curve, due to its input, there are two different threshold voltage, so this circuit is used as the electronic switch, all kinds of control circuit, waveform transformation and cosmetic purposes,
1) waveform transformation (such as separating the triangle wave, sine wave into a rectangular wave),
2) pulse wave shaping (digital systems, often occurs in rectangular pulse waveform distortion, rose along the falling edge and not the ideal situation, can be used after the Schmitt trigger plastic, obtain ideal rectangular pulse),
3) pulse as picture (amplitude, irregular pulse signal applied to the Schmitt trigger input, can choose bigger than to set the value of pulse signal is output),

Second,
Using op-amp constructs the Schmitt trigger, set the op-amp only one input (in phase or reverse side) as a benchmark potential, access feedback at the same time, the input signal from the other end of the input, and make its amplitude between the power supply voltage range,





I tell in my own understanding of the way:
Schmidt is to prevent at a certain critical level of the jitter of problem situations, in order to stabilize our output, and design