L293D IC is the most commonly used IC apart from 555 timer IC (which is used to produce time delay). Used to control the motor which you might often use in your big projects like drones, CNC plotters, etc.
These L293d IC are beneficial in the sense that offered:
- H-Bridge Circuit
- Providing External Supply other than Microcontroller
Why do we need to use L293d IC
Microcontrollers like Arduino don’t carry the ability to provide the voltage more than 5V, although many microcontrollers can’t. To run the motor at its high speed we need voltage more than that, to overcome either we need to use MOSFET or transistor. The MOSFET or transistors allow us to take power from external sources by keeping the ground of the power source as well as microcontroller common.
There is one more thing that, we know that the motor can run in two directions. If we were to use the motors with the help of transistor (to provide external power) with Arduino directly. Then we would not be able to change the direction of the motor unless you have made the H-Bridge.
These two limitations are covered by the L293D IC which has both H-Bridge in it as well as it supports the use of external power. Therefore you get two big chunks of circuit removed by this just single IC.
Why do we need to read the L293d Datasheet
The datasheet contains the information about the various IC pins, the L293d IC is 16 pin IC. If you are a newbie to the ICs then you can’t remember the function of all the pins. There are total of 4 pins to receive the motor inputs, which means you can run two DC motors.
There are two pins for grounds and two for taking input from your microcontroller (the pins which you attach to the Arduino). There is pin no.8 for the positive end of your external power supply.
The negative end of the power supply, as well as the Arduino ground, should be connected.
Before reading L293D Datasheet
Before reading the datasheet of the IC, you need to know some basic things about it - where the numbering of pins start on the ICs.
You can observe on your Ic that there is semicircle made over it, it indicates that your IC numbering start from that side. But from left or right?
IC reading starts from the left to the semicircle if semicircle is ahead of you.
Image Description for L293D Datasheet
- Enable (1,2): driver output at 1 and 2 pins.
- Input Pins: input to IC by connecting the wires from Arduino.
- Output Pins: outputs to the motor.
- Vcc 2: external supply for your IC in case your microcontroller can’t supply enough power.
- GND: ground connections (you should connect to your Arduino ground).
Download L293D Datasheet
Now I think you are ready to read the datasheet of the L293D IC which you will understand easily. Above I provide the link to download L293D Datasheet PDF.