L293d H-Bridge Motor Driver IC: What Is, Types, Working Principle (Quick Guide)

In this article, you will learn how to control the DC motors. For this, the l293d motor driver can play a major role. It can control the speed and direction of the motor. It can also maintain a bipolar stepper motor NEMA 17. So, let’s learn all about the L293d motor driver.

What Is Motor Driver IC?

A motor driver IC allows the DC motor to drive in any direction. It controls the motor by regulating the voltage and current supplied. Motor Driver ICs were based on the types of motor drivers. Its phase configurations, interface, qualification, package type, etc.

L293D Motor Driver ICs are used in robotics, automotive electronics, autonomous robots, and various office appliances.

How L293D Motor Driver IC Works?

l293d motor IC uses two techniques for the control speed and rotation of the DC motors. The L293D works by using an H-Bridge to control the direction of the motor.

An H-Bridge circuit contains four elements. Transistors with the motor, H-Bridge at the configuration. After that, you can change the direction of the current flow. In this way, you can change the direction of the motor.

A motor requires a control switch to turn on or off the motor. To reverse the direction of the motor, you can use the polarity poles. The polarity can be achieved by four switches that can be arranged to control the direction.

These motor circuits are used mainly in different converters. These converters are DC-DC, DC-AC, and AC-AC converters. It has four switches.

S1, S2, S3, and S4. In which S1 and S4 switches are closed. When it suddenly stops, the motor terminals are shorted. When it’s detached from the circuit then it stops the motor.

L293D Motor Driver IC Pin Diagram Configuration

According to the pin diagram for the L293D IC, this summary provides a breakdown of each of its 16 pins.

• Enable 1-2 (Pin No. 1): A strong pin controls the left side of the IC. When it is high (or at logic level 1), the left side turns on and works. When it is low (or at logic level 0), the left side is turned off and does not work. Remember to check the important notes at the end of the description.
• Input 1 (Pin No. 2): This pin takes a control signal (usually from a microcontroller) that decides which direction the left motor will turn.
• Output 1 (Pin No. 3): This pin connects to one of the terminals of the motor. This corresponds to the state of input 1, when input 1 is high it is high, and when input 1 is low it is low.
• Ground (Pin No. 4 and 5): These pins are used for grounding and as a heat sink to manage excess heat. This is important because running two motors increases the load, and without proper grounding, the IC may overheat and be damaged.
• Output 2 (Pin No. 6): This pin works like output 1 but gets connected to the other terminal of the left motor. It goes high or low depending on input 2.
• Input 2 (Pin No. 7): This pin works just like input 1 but controls the direction of the left motor based on signals from the controller.
• VCC2 (Pin No. 8): This pin supplies power to the IC for both motors, which require a voltage between 4.5V and 36V to operate properly.
• Enable 3-4 (Pin No. 9): This pin performs the same function as Enable 1-2 but controls the right side of the IC. It enables the right side when it is high and disables it when it is low.
• Input 3 (Pin No. 10): This pin receives a signal to control the direction of the right motor, similar to inputs 1 and 2.
• Output 3 (Pin No. 11): Connected to the right motor terminal, this pin behaves like output 1, going high or low depending on the state of input 3.
• Ground (Pin No. 12 and 13): These pins also act as ground and heat sinks, which are necessary to manage the load from the two motors and keep the IC from overheating.
• Output 4 (Pin No. 14): This pin connects to the other terminal of the right motor and changes state depending on input 4, similar to the other output pins.
• Input 4 (Pin No. 15): This pin determines the correct motor direction of motion, receiving control signals like other input pins.
• VCC1 (Pin No. 16): This pin provides power to the entire IC and needs to be supplied with 5V. Without 5V, the IC will not work.

Important Note:

• You can control the speed of the motors by applying a PWM signal to enable pins 1-2 and enable pins 3-4. Applying signals to enable 1-2 controls the speed of the left motor, and to enable 3-4 controls the speed of the right motor.
• To handle higher currents, the L293D IC includes four ground pins to help with heat dissipation. These are important for the protection of the IC, especially because there is a large metal area between the ground connections on the PCB that helps dissipate heat.

What Are The Various Applications Of L298 Motor Driver IC?

The applications of L298 motor driver IC include the following.

• 1. Different embedded systems
• Robotics, DC motors, and controlled DC motors.
• High power-based applications.
• The control unit provides only TTL outputs.

Features And Characteristics Of L293D IC

In the following, I have mentioned L293D Motor Driver IC features and characteristics:

• Voltage range supported: 4.5V to 36V
• Each channel can handle up to 600mA of current
• Each channel can reach up to 1.2A of current at peak
• Designed to withstand high electrical noise
• Separate power supply for the control logic
• Includes built-in protection against static electricity (ESD)

Setting Up L293D Motor Driver With Arduino:

Below is a simplified guide to connecting your components so that you can control the DC motor to move in different directions (forward, backward, right, and left) using the Arduino. Arduino is powered via a USB cable. Pin 16 of the L293D motor driver gets power from the 5V output pin of the Arduino. A 9V battery is connected to pin 8 of the L293D to provide the additional voltage required for the motor.

The output pins (3, 6, 11, and 14) of the L293D connect to the terminals of the DC geared motor.

The inputs of the L293D (pins 2, 7, 10, and 15) are connected to the digital pins of the Arduino (5, 4, 3, and 2) in that order.

The pins labeled Enable 1-2 and Enable 3-4 of the L293D must be connected to the 5V line to activate the motor control.

Below, you will find a code snippet to upload into your Arduino IDE. This will help you test the motor control and see it in action.

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