Working of Schmitt Trigger
The comparator works properly when the input signal does not contain any noise. If the noise is present than comparator does not work properly. When the noisy signal is present, the Schmitt trigger gives proper results. It uses two threshold voltages i.e., upper threshold voltage (VUT) and lower threshold voltage (VLT). Let us understand the working of Schmitt Trigger with the help of given graph.
From the above diagram, the signal which is red in color is the noisy signal. When the signal value is lower than upper threshold voltage, the output voltage remains in low state (‘0’ state). When the upper threshold value is crossed by the noise signal, the output voltage moves to high state (‘1’ state). The output signal will change its state to low when the noisy signal crosses the lower threshold value.
Noisy Signal Value (Vn) | Output Signal State (Vout) |
---|---|
Vn> VUT | High State (‘1’) |
VLT < Vn < VUT | Remain in the previous state |
Vn< VLT | Low State (‘0’) |
In this way the Schmitt Trigger works and helps in preventing continuous switching in the device due to noisy signal.
Schmitt Trigger
We use Schmitt Triggers in digital electronics. It is used for rejecting the noise from the input signals by using the hysteresis curve. To provide accurate and more stable results, it uses two threshold voltages i.e., upper threshold voltage (VUT) and lower threshold voltage (VLT). It is mainly used in signal conditioning applications to remove noise from signals which is used in digital circuits, particularly mechanical contact bounce in switches. In this article, we will learn more about Schmitt Trigger, its working, and its applications.
Table of Content
- What is Schmitt Trigger?
- Working
- Transfer Characteristics
- Types
- Uses
- Schmitt Trigger Vs Comparator
- Advantages and Disadvantages
- Applications