Back to analog, let us start some Schmitt trigger experiments with jellybean bipolar junction transistors… This post explores the classic emitter-coupled Schmitt Trigger circuit. A Schmitt trigger is ...

Figure 1 Use a portion of a programmable-logic device or gate array to implement a Schmitt-trigger buffer (a) by adding either two (b) or four external resistors (c). Thanks to its internal hysteresis ...