What is the characteristic and classification of Digital Logic Gate Circuit?

( 1 ) Characteristics of digital circuit digital logic gate circuit referred to as digital circuit, which has the following characteristics :

1 ) strict logic.

2 ) Strict timing.

3 ) There are only two logical levels ( or pulses ).

4 ) The magnitude of the level corresponding to the logical value ( 0 or 1 ) varies depending on the actual circuit.

5 ) The firmware feature is obvious. Because the digital circuits deal with logic level signals, from the perspective of signal processing, digital circuits have higher signal anti-jamming than analog circuits ability.

( 2 ) Classification of digital circuits

1 ) Digital circuits can be divided into small scale, medium scale, large-scale and super-large scale, according to the integration degree.

A small scale digital circuit ( SSI ) is usually a logic unit circuit, such as a logic gate, a trigger, etc.

MSI is usually a logic function circuit, such as decoder, data selector, counter, register and so on.

 Large scale digital circuits ( LSI ) and very large scale digital circuits ( VLSI ) are usually a small digital logic system and have been made into a larger scale modular digital circuit.

2 ) According to polarity, digital circuits can be divided into bipolar circuit and unipolar circuit.

The representative of the bipolar circuit is the TTL circuit. Besides the standard form, there are four other structural forms : high speed TTL ( 74H series ), low power TTL ( 74L series ), ultra high-speed TTL ( 74S series ) and low power Schottky TTL ( 74LS series ).

 In high-speed CMOS circuits, the 74HC and 74HCT series correspond to the TTL 74 series, and the main difference is that the supply voltage is different, 74HCT series and 74LS series supply voltage are the same, level matching, interchangeable, 74HC series power supply voltage between 2 ~ 6V optional, there is a level matching problem with the 74LS series, which cannot be directly interchanged.

( 3 ) When using digital circuits, digital circuits must correctly understand the significance and value of electrical parameters and use them according to regulations. In particular, we must strictly observe the limit parameters, because even if the moment is exceeded, the device will be damaged. When using the gate circuit, you should know the name of the circuit and the arrangement of the pins.

This article is from Allicdata Electronics.