L293D Motor Driver Characteristics, Technical Parameters, Advantages and Working Principle
22 February 2024
Ⅲ. Technical parameters of L293D
Ⅴ. L293D motor driving principle
Ⅷ. Wiring method of L293D motor drive module
Ⅸ. L293D development history and trends
L293D is a commonly used dual H-bridge DC motor driver chip used to control stepper motors, DC motors and various other types of loads. In this article, we will introduce its characteristics, working principle, technical parameters, advantages and applications so that you can better understand this chip.
L293D is a basic motor driver integrated chip that can drive a DC motor in any direction and regulate the speed of the motor. Generally speaking, with a single L293D we can run up to two DC motors. It consists of two H-bridge circuits. H-bridge is one of the simplest circuits used to change the polarity of the load connected to it. The L293D is equipped with 2 output pins, 2 input pins and 1 enable pin for driving each motor. It is designed for driving inductive loads such as relays, solenoids, DC motors and bipolar stepper motors, as well as other high current or high voltage loads.
Alternatives and equivalents:
• L293DD
• L293DNE
• L293E
• L293NEG4
• Adjustable supply current: It allows the user to adjust the output current through external components to suit different types of motors.
• Wide operating voltage range: L293D can operate in the range of 4.5V to 36V, suitable for a variety of power supply systems.
• Low circuit complexity: L293D requires only a few external components to realize motor driving, greatly simplifying circuit design.
• Logic level compatible: Its input port logic level is compatible with TTL and CMOS levels, making it easy to connect with other digital circuits such as microcontrollers.
• Overheating protection function: L293D integrates overcurrent protection and overtemperature protection circuits. When the current or temperature exceeds a certain threshold, it will automatically cut off the power supply, effectively protecting the chip from damage.
• Dual H-bridge drive: L293D integrates two H-bridges internally, which can control the forward, reverse and braking functions of two DC motors respectively. Each H-bridge can provide a maximum output current of 600mA.
• H-bridge current (IGND): The pin IGND of L293D is used to provide the driving current of the H-bridge. The voltage range of this pin is generally the same as the VCC voltage.
• Maximum output current (IO): The output pin of L293D can provide a maximum current of 600mA for driving a DC motor. This value is sufficient for most small DC motors.
• Driving power supply voltage (VCC): The operating power supply voltage range of L293D is generally 4.5V to 36V. When in use, the VCC voltage should be determined based on the rated voltage of the connected DC motor.
• Control logic voltage (VCC1): The control electrical signal of L293D uses 5V logic level. The voltage range corresponding to the high level (1) and low level (0) of the control pin is 0V to VCC1.
• Pin configuration: L293D has a total of 16 pins. Among them, 8 pins are used to control the rotation direction of the DC motor, 4 pins are used to input control signals, and the other 4 pins are used to connect VCC and GND.
L293D has the advantages of strong driving capability and ease of use. Its driving capacity can reach 3A, which can meet the needs of most motors. At the same time, its high degree of integration can reduce the area of the circuit board and make the circuit design more compact. We only need to simply connect the power supply and input voltage to control the rotation direction and speed of the motor.
L293D can realize different states of the motor such as forward rotation, reverse rotation, braking and floating by controlling different combinations of input signals. L293D has a total of 16 pins, of which 1 to 4 and 9 to 12 are control input pins, 5, 6, 7, 8 and 13, 14, 15, and 16 are motor output pins. The control input pin can control the status of the motor by connecting to a high or low level, and the motor output pin is directly connected to the motor. During the working process of L293D, different combinations of control input pins can achieve different motor states. For example, when pins 1 and 2 are connected to high level and pins 3 and 4 are connected to low level, the motor will rotate forward; when pins 1 and 2 are connected to low level and pins 3 and 4 are connected to high level, the motor will rotate forward. It will reverse; when pins 1, 2 and 3 and 4 are all connected to high level, the motor will brake; when pins 1, 2 and 3 and 4 are all connected to low level, the motor will float. It should be noted that the input voltage of L293D must be between 4.5V and 36V, and it also needs some external components such as capacitors and fuses to ensure its normal operation.
L293D is often used in the following fields:
• DC motor driver: The L293D can control the direction of rotation and speed of a DC motor. By controlling the level of its input pins, the motor can be operated forward, reverse, brake and stop.
• Small vehicle projects: We can use the L293D to control motors in small vehicles. For example, in the smart car project, L293D also shows powerful control ability. Intelligent vehicles need to navigate, avoid obstacles, and accomplish tasks autonomously in a variety of complex environments, and the L293D is able to provide reliable motor drive support for intelligent vehicles. By accurately controlling the rotational direction and speed of the motor, it helps the intelligent vehicle achieve smooth driving and precise steering, thus ensuring that the intelligent vehicle can successfully complete various tasks.
• Fan control: By carefully adjusting the signal input to the L293D, we can easily control the direction of rotation of the fan. When the input signal is set to a specific mode, the fan will rotate in one direction to bring us cool breeze; while changing the mode of the input signal, the fan will rotate in the opposite direction to change the wind direction.
• Robotics: The L293D is widely used to control motors for robots, including wheeled mobile robots and gait robots. For wheeled mobile robots, the L293D enables the robot to move and steer precisely by controlling the speed and direction of the motors. This enables wheeled robots to flexibly navigate, avoid obstacles, and perform a variety of tasks. As for gait robots, L293D realizes stable walking and balance control of the robot by controlling the motors' movement and coordination.
1. Power supply wiring
The L293D motor driver module has two power input ports, one is VCC and the other is VS. VCC is the power input port of the control circuit, which connects to the 5V power supply; VS is the power input port of the power circuit, which connects to the power supply of the motor.
2. Control signal wiring
The control signals of the L293D motor driver module are divided into two channels, corresponding to the forward and reverse control of the two motors. The input method of control signal can be PWM signal or common digital signal. The specific wiring is as follows:
(1) IN1 port: connect to control signal 1, used to control the forward and reverse rotation of motor 1.
(2) IN2 port: connect to control signal 2, used to control the forward and reverse rotation of motor 1.
(3) IN3 port: connects to control signal 3, which is used to control the forward and reverse rotation of motor 2.
(4) IN4 port: connect to control signal 4 for controlling the forward and reverse rotation of motor.
3. Motor wiring
The motor wiring of the L293D motor driver module has two ports, corresponding to the power and control signals of the two motors. The specific wiring is as follows:
(1) OUT1 port: connect to the positive pole of motor 1.
(2) OUT2 port: connect to the negative pole of motor 1.
(3) OUT3 port: connect to the positive pole of motor 2.
(4) OUT4 port: connect to the negative pole of Motor 2.
L293D was developed by NEC in the early 1980s and was mainly used in automotive electronics at that time. With the rise of fields such as robotics, smart homes and smart vehicles, it has gradually gained wide application. Meanwhile, with the rise of emerging fields such as electric vehicles, the application of L293D is also expanding. During the development process, the specifications and performance of L293D have been continuously upgraded. The capabilities of the L293D are continuously broadening, transitioning from an initial 4A current output to 1.2A, and from a dual H-bridge to a quad H-bridge configuration, thereby expanding its functionalities and application domains.
In the future, the L293D chip will focus more on power density, integration and reliability to meet the growing market demand. At the same time, the application of L293D chips will be more extensive, not only including DC motors, stepper motors and other traditional areas, but also involving more areas, such as electric vehicles, intelligent transportation and so on.
The future development trend of L293D chips may include the following aspects:
1. Improvement of integration: L293D chips need more functions and smaller size to fit more application scenarios.
2. Improvement of reliability: L293D chips need to have higher reliability to ensure the stability and safety of the motor control system.
3. Expansion of application fields: The application fields of L293D chips will continue to expand, including electric vehicles, intelligent transportation, aerospace and other fields.
4. Increase in power density: As the power of the motor continues to increase, the L293D chip needs to have a higher power density to meet the growing market demand.
Frequently Asked Questions
1. What is a L293D?
The L293D is designed to provide bidirectional drive currents of up to 600-mA at voltages from 4.5 V to 36 V. Both devices are designed to drive inductive loads such as relays, solenoids, DC and bipolar stepping motors, as well as other high-current/high-voltage loads in positive-supply applications.
2. Can L293D control motor speed?
Moreover, the L293D also provides a means to control the motor's speed through a technique called Pulse Width Modulation (PWM).
3. Which is better L293D vs L298N?
L293D is a quadruple motor driver that employs a half-H driver, whereas L298N is a dual full-H driver, which means that in L293D all four input-output lines are independent, whereas in L298N a half-H driver cannot be utilized separately, and only a full H driver may be used.
4. Why do we use L293D motor driver?
The L293D is a 16-pin Motor Driver IC which can control a set of two DC motors simultaneously in any direction. The L293D is designed to provide bidirectional drive currents of up to 600 mA (per channel) at voltages from 4.5 V to 36 V (at pin 8!). You can use it to control small dc motors - toy motors.
