How does the comparator work, is it just a comparison? ?

Photocoupler

Guide: A comparator , as its name suggests, is a device that can compare two or more data. This article mainly introduces the working principle of the comparator . Let's learn about how the comparator works together with Xiaobian~~~

1. Comparator working principle - introduction

A comparator is a circuit or device that enables two or more data items to be compared to determine if they are equal, or to determine the size relationship and ordering order between them. A comparator is a circuit that compares an analog voltage signal with a reference voltage. Its two inputs are analog signals, and the output is a binary signal. When the difference of the input voltage increases or decreases, the output remains constant. The threshold of the comparator is fixed, some have only one threshold, and some have two thresholds.

2. Comparator working principle - classification

The two inputs of the comparator are analog signals, and the output is a binary signal. When the difference of the input voltage increases or decreases, the output remains constant. There are many types of comparators, which are mainly divided into the following types:

1) Voltage comparator: The voltage comparator is obtained by changing one input of the zero-crossing comparator from ground to a fixed voltage value.

2) Window Comparator: The circuit consists of two amplitude comparators and some diodes and resistors. When the potential level of the high level signal is higher than a certain value VH, the comparison circuit is positively saturated. When the potential level of the low level signal is lower than a certain value VL, the comparison circuit is negatively saturated.

3) Hysteresis comparator: A resistor divider branch is connected from the output to the non-inverting input. When the input voltage vI gradually increases from zero, and the VI upper limit threshold level. When the input voltage VI > VT, VT is called the lower threshold (trigger) level.

3. How the comparator works

As shown in the figure below, the relationship between the analog input voltage of a single comparator and the digital output. When the analog input VIN+ voltage is lower than the VIN– voltage, the comparator outputs a digital low. When the analog input VIN+ voltage is higher than VIN–, the comparator outputs a digital high. The shaded area of ​​the comparator output section in the figure below is the uncertainty zone due to input offset and response time.

Depending on the mode of operation, the comparator can use an external or internal reference source. The analog output of the VIN– is compared to the VIN+ signal, and the digital output of the comparator changes.

The working principle of the comparator has been introduced. The following is a few good articles compiled by Xiaobian for everyone. If you are interested, please take a look at it. It is very upright~~~

1. How the comparator works

2. The working principle and application examples of voltage comparator

3. Voltage comparator principle

Analog signal