A Schmitt trigger is a semiconductor device that can function as a level detector or a switching element with hysteresis. The presence of hysteresis can be used, for example, to eliminate chattering during switching caused by noise in the switching signal. In an optical encoder, a noisy signal detected by the photosensor may be converted into a clean signal of rectangular pulses by this means. The I/O characteristic of a Schmitt trigger is shown in Figure P6.48a. If the input signal is as shown in Figure P6.48b, determine the output signal.
Figure P6.48
