Learning about 74HC14 Hex Inverting Schmitt Trigger IC

74HC14 Hex Inverting Schmitt Trigger IC is widely used in digital logic circuits. It has six independent inverters which accounts for the Hex term, and Schmitt trigger input. Each inverter converts its input signal into its logical complement, meaning that it will convert from high to low or low to high states. Typical operating voltage ranges from 2 to 6 Volts. It is a 14 pin integrated circuit available in DIP14 plastic package suitable for mounting on a solderless breadboard and also as SMD package. 74HC14 has high noise immunity characteristic of CMOS (complementary metal-oxide semiconductor) devices. Oscillators, time delay circuits, analog to digital and digital to analog converters, pulse shaping and waveform generation are some of the applications for 74HC14 IC.

Schmitt trigger is a circuit with hysteresis implemented by applying positive feedback to the non inverting input of a differential amplifier. It is called a trigger because the output retains its value till the input changes sufficiently to trigger a change. When the input goes above a chosen threshold, output is high. When it goes below a different chosen lower threshold, output is low. When the input is between the two chosen levels, the output retains its value. This dual threshold action is called hysteresis and implies memory of past state for the Schmitt trigger. It is useful in converting analog signals to digital signals and for removing noise from signals used in digital circuits.