L293D the driving chip
When you think of the word ‘l293d’, what comes to mind? If you’re like most people, you probably think of something like, ‘Oh, that’s the chip that drives my robot!’ Right? Or maybe “Oh, that’s the chip that allows my robot to move!”. In this post we will explore what l293d actually is and how it does exactly what it does.
A bit of history
Let’s start at the beginning: l293d stands for ‘Lane-Encoder-Data-Logger’. It was developed by National Semiconductor (now Texas Instruments) in 1982 as part of the LM2903 series of integrated circuits (ICs). The ICs were specifically designed for use in line sensors and encoders, which are devices used to measure position and speed. They are also used in devices such as linear actuators, which are motors that rotate along a single axis.
The L293D is an excellent driver for double H-bridge motors with integrated freewheeling diodes. It is typically used to control two DC motors or two bipolar stepper motors, but can also be used to drive four single-pole stepper motors (or two bipolar stepper motors) with external transistors.
Operation of the L293D
The LM2903 consists of three main parts: an analogue switch, a comparator and an output amplifier. The analogue switch allows current to flow through one port or another based on the difference between two voltages or, more precisely, the comparison between two voltages. For example, if one port is connected to ground and the other is connected to 5 volts, then current will flow through this port when the voltage at point A is greater than the voltage at point B. This process is called comparison, because it compares two voltages to determine which one should be sent through the output port of the analogue switch.
To drive one DC motor or two bipolar stepper motors, the L293D requires a minimum supply voltage of 7V to 12V and a maximum of 36V and can handle up to 1A per channel for a total current of 2A. The chip is equipped with thermal shutdown protection to prevent damage in the event of overheating.
When driving four unipolar or two bipolar steppers, the chip requires a minimum supply voltage of 4.5-6V and a maximum of 36V, and can handle up to 1A per channel for a total current of 4A.
Driver applications
The L293D is intended for driving small motors in battery-powered applications such as R/C models and other toys, but can also be used in other applications requiring a high-current driver.
The L293D H-bridge can be used to control the direction of current flow in a circuit. The chip can be used to control the direction of current flow through a motor, allowing it to turn in either direction. This is useful for a number of applications, including robotics, 3D printers and other machines that require motors.
The chip can also be used to control the speed of an electric fan, turning it on and off at different speeds. This is done by simply changing the on and off frequency of the chip.
L293D H-bridges are also commonly used as variable voltage regulators. By connecting them in parallel with a power supply, they can adjust the voltage output from the power supply to match what needs to be regulated.
Conclusion
The L293D is an excellent motor driver chip that can be used to control two DC motors. It has many features that make it reliable and easy to use, including built-in protection against reverse polarity, overcurrent and thermal overload. It is an ideal motor driver for beginners who want to learn how to control motors with a microcontroller.
In conclusion, we recommend the l293d as the best motor driver for most applications. It has great power and torque and can be used in both high-current and low-current applications.