L298 Motor Driver IC : Pin Configuration & Its Applications

An L298 Motor Driver IC is a monolithic chip, used in motor driver modules to control the speed of a DC motor. At present, the most frequently used motor driver ICs as compared to L298 is; L293D & L2938N. This IC is frequently used in RC cars & autonomous robots. The input provided to a motor driver module is taken from a controller like Arduino.

So this logic input is simply used to control the direction of the motor which is connected to the motor driver IC. The motor driver module mainly includes a motor driver IC, which is an essential component in this module. This single IC can control the motor alone but using the motor driver module by interfacing it with Arduino can make it easy. This article discusses an overview of L298 motor driver IC, working with applications.

What is L298 Motor Driver IC?

The high-power version of the L298 IC is an L293 motor driver IC. It is a dual full-bridge driver IC with high current & voltage, mainly designed to allow typical TTL logic levels to control different inductive loads like DC motors, solenoids, relays, stepper motors, etc. The motor driver is a small current amplifier that uses a low current signal to provide a high current signal for driving an electric motor.

L298 IC includes four separate power amplifiers where two amplifiers can form H-bridge A and the other two types of amplifiers can form H-bridge B. Here, One H Bridge is used to switch the polarity to control the motor direction whereas pair of H bridges are used for controlling a bipolar stepper motor.

Each bridge in this IC includes two current sense pins like CSA & CSB and enable pins like ENA & ENB. Here, current sense pins are connected to the ground terminal but we can also include a low-value resistor where its voltage reading is relative to the current. Similarly, enable pins can also be used to make all the outputs active simultaneously. All the enable and input pins in this IC work with 5V TTL logic to make the connection simple with different types of microcontrollers.

Pin Configuration:

The pin configurations of L298 dual full-bridge driver IC include 15-pins where each pin is discussed below. This IC includes dual bridges namely; H-bridge A & H-bridge B.

• Pin1 (Current Sensing A): This pin is used to control the flow of the current of the load.
• Pin2 & 3(Output 1 & 2): These two pins are output pins of the H- Bridge A where the current supplies throughout the load which is monitored at pin-1
• Pin4 (VS): This is a voltage supply pin, connected to +5V.
• Pin5 & 7 (Inputs): Control Inputs of the Bridge A & compatible with TTL
• Pin6 (Enable A): This is an enable input with TTL compatible
• Pin8 (GND): This is a GND pin
• Pin9 (Logic Voltage Supply): This pin provides voltage supply for the logic blocks.
• Pin10 & 12 (Inputs3 & 4): These are control inputs of bridge-B and compatible with TTL
• Pin11 (Enable B): This is an enable Input with TTL compatible
• Pins 13 & 14 (Output 3 & 4): These are output pins of the H- Bridge B where the flow of current throughout the load is monitored at pin15.

Features & Specifications:

The features and specifications of L298 IC include the following.

• The operating voltage supply is up to 46 v.
• Total DC is up to 4A.
• The saturation voltage is less.
• Protection from over temperature.
• Power dissipation is 25w.
• Operating voltage ranges from +5 to +46v
• The maximum voltage supply voltage is 50v.
• Maximum input & enable voltage is +7v.
• TTL controlled inputs.
• Storage temperature ranges from -40°c – 150°c.
• Operating temperature ranges from -23°c to – 130°c.
• The maximum allowed the current flow to draw through every output is 3a.

How to use L298 Motor Driver IC/Circuit Diagram

To understand the working of the L298 motor driver IC, consider the following simple circuit configuration. In this circuit, one of the H Bridge of l298 IC is used. This circuit can be designed with two push buttons which are denoted Q1 & Q2. These pushbuttons are used to control the inputs of bridge-A.

Here, these logic inputs are provided through a microprocessor or a microcontroller within application circuits. The four diodes used in the circuit are flyback diodes that protect the IC from voltage spikes.
Here, the function of bridge-A mainly depends on the enable pin. Once the enable pin is pulled high using a resistor then Bridge-A will enable and start working. Similarly, when it is pulled to GND, it will be disabled so stops working.

Once the circuit is connected, we need to push the two buttons like Q1 & Q2 for changing the current flow among two output pins like OUT1 & OUT2

The logic control follows as

• When Push buttons Q1 is high and Q2 is low then it is forward current.
• When Push buttons Q1 is low and Q2 is high then it is reverse current
• When both the pushbuttons are equal like Q1=Q2 then it is a quick motor stop

If the Q1 push button is pressed then the current starts flowing from Output to Output2 the motor’s rotating direction will be clockwise. Similarly, If the Q2 push button is pressed, the current starts flowing from Output2 to Output1 then the motor direction will be in the anti-clockwise direction.

If both pushbuttons like Q1 & Q2 are simultaneously pressed or released then the motor will be stopped immediately. So, in this way, the motor speed can be controlled through an L298 motor driver IC.
Please refer to this link to know more about L298 Motor Driver IC Datasheet.

Where to use L298 Motor Driver IC/Applications:

The applications of L298 motor driver IC include the following.

• L298N motor driver IC is used in different fields like robotics, embedded, etc. We know that microcontrollers work with very little voltage and current but motors use high voltage and current. So, for this reason, motor driver ICs are used to provide high voltage and current.
• L298 motor driver is applicable where H- BRIDGE is used.
• This motor driver is used in high power-based applications.
• This IC is used where current control & PWM operable IC is required.
• This IC is used where the control unit provides only TTL outputs.

Please refer to this link to know more about L298 Motor Driver IC Datasheet

Thus, L298 Motor Driver IC can also be used to control the motor direction. There are different types of motor driver ICs available in the market based on the maximum voltage supply, load voltage, maximum o/p current, rated power dissipation & number of outputs. Generally, the L298 motor driver IC is used to control dc motor speed. By using this IC, dc motor interfacing with a microcontroller is simple. Here is a question for you, please mention different motor driver ICs.