What is 7474 IC
The 7474 is a dual rising edge triggered D-type flip-flop integrated circuit with preset clear and complementary outputs. Preset or clear the low level setting on the input or reset the output regardless of the level of the other inputs. It features direct output to CMOS, NMOS and TTL interfaces, a wide operating voltage range and wide operating conditions.
This article is mainly to introduce you to the 7474 pin and 7474 circuit diagram.
This device contains two independent positive-edge-triggered D-type flip-flops with complementary outputs. Information on the D input is accepted by the flip-flops on The positive going edge of the clock pulse. At a voltage level and is not directly related to the transition time of the rising edge of the clock. The D input may be changed while the clock is LOW or HIGH without affecting the outputs as long as the data Setup and hold times are not violated. A LOW logic level on The preset or clear inputs will set or reset the outputs Regardless of the logic levels of the other inputs.
Key Features of 7474 IC
- Two D-Type Flip-Flops
- Outputs Directly Interface to CMOS, NMOS and TTL
- Large Operating Voltage Range
- Wide Operating Conditions
- Not Recommended for New Designs Use 7474
7474 Pin Description
The 7474 has 14 pins, each with its own purpose, to enable the chip to implement circuit functions. The figure below shows the pinout of the 7474:
- PIN 1– clear 1 input
- PIN 2–D1 input
- PIN 3–clock 1 input
- PIN 4–preset 1 input
- PIN 5–Q1 output
- PIN 6–complementary Q1 output
- PIN 7–ground
- PIN 8–complementary Q2 output
- PIN 9–Q2 output
- PIN 10– preset 2 input
- PIN 11–clock 2 input
- PIN 12–D2 input
- PIN 13–clear 2 input
- PIN 14–positive power supply
The circuit schematic can help us better understand the circuits and components used, and it is a reference for the actual circuit to work properly. Below is a fully labeled 7747 schematic for reference.
With reference to the 7474 feature, the first scenario we can think of is that it has two D-type flip-flops.
In addition to a feature, we may need to know some other features that can help us make good use of it, for example, VCC operating between 4.75V and 5.25V, the minimum input voltage is 2V, the maximum The maximum value of the value. The low-level input voltage is 0.8V, the maximum value of the high-level output current is -0.4mA, and the maximum value of the low-level output current is 16mA.