Hysteresis in electronics refers to a phenomenon where the output of a system depends not only on the current input but also on the history of past inputs. In other words, the output of the system lags behind changes in the input, and the system retains some memory of its previous states.
This concept is commonly encountered in various electronic devices and systems, such as sensors, amplifiers, and switches. The presence of hysteresis is intentional in some cases as it can be used to add stability, prevent rapid switching, or create memory in a circuit.
One common application of hysteresis is in the design of Schmitt triggers. A Schmitt trigger is a type of comparator with positive feedback that introduces hysteresis to the input-output relationship. It has two voltage thresholds: a higher threshold (Vhigh) and a lower threshold (Vlow). When the input voltage rises above Vhigh, the output switches to its high state, and it remains in that state even if the input voltage slightly decreases. The output only switches to its low state when the input voltage falls below Vlow, and it stays in the low state until the input voltage rises above Vhigh again. This hysteresis prevents the output from toggling rapidly when the input voltage is near the threshold, which helps reduce noise and improve stability in noisy environments.
Hysteresis can also be found in magnetic materials, where it describes the lag in the magnetization of a material with changes in the magnetic field. This property is important in the design of devices like magnetic memory storage and magnetic sensors.
In summary, hysteresis in electronics is a valuable concept that allows for stability, noise reduction, and memory effects in various electronic circuits and systems.