Comparator with hysteresis (Schmidt trigger) can be built using LM339, LM239, LM2901, LM2901V, NCV2901, or MC3302 quad single supply comparator integrated circuit chips. Here is the circuit’s schematic diagram and formula:
This circuit’s output will swing to high or low using two threshold values. If the last output is high, then the output can be changed to low if the input swing above upper threshold point, and after the output is low, then it can be changed to high after the input falls under lower threshold point. You can use the formula shown in the figure to select the component values. [Circuit's schematic source: Motorola Application Notes]
Possibly Related Articles:
- Non-Inverting Comparator With Histeresis
This circuit has similar function with inverting comparator with hysteresis, but the output is not inverted. The output will be high if the input is higher than the upper threshold... - Square Oscillator Using Comparator: The Circuit Schematic Diagram and The Formula
Using a single supply quad comparator LM339, LM239, LM2901, LM2901V, NCV2901, or MC3302, we can build a square-wave oscillator with simple circuit and formula. Here is the schematic diagram: This... - 555 IC Oscillator with 50% Duty Cycle
A square wave oscillator using 555 IC can be configured to give symmetric oscillation (50% duty cycle). Other circuit uses diodes to split the charging and the discharging paths through... - Wien Bridge Oscillator: The Circuit Schematic Diagram and The Design Formula
The excellent high input impedance, high slew rate, and high voltage qualities of CA3140 op-amp make it suitable for Wien-bridge sine wave oscillator. The basic circuit for Wien-bridge sine wave... - Amplitude Average Detector
This circuit is similar to peak detector, but the the output won’t immediatelly follow the input peaking. Because the output follow the input peak slowly, averaging effect will be seen...
| 
