L293 is the most widely known dual motor HBridge drive IC in Robotics.It can drive bipolar motors as well as Stepper motors.
L293 can drive two motors at a time with source 600mA current for each motor.The L293 comes in a standard 16-pin, dual-in line integrated circuit package. There is an L293 and an L293D part number. “D” version has built in fly back diodes to minimize inductive voltage spikes
The L293 has an automatic thermal shutdown which means the chip will stop working if it gets too hot.If the L293 is getting too hot you can get another L293 and solder it piggy back on top of the first. This will double the drive current.
For current requirements of 2A you can use L298 & for still higher currents opt for MOSFET driven H Bridges.
Each motor is driven clockwise or anticlockwise according to the Logic levels at Input pins & Enable pin as shown in figure below :
L293 is available in market on break out board which is handy to use in projects.The board has a built in 7805 regulator to power up L293 with 5v at pin 16.Motor connection pins are extended using berg pins. The control pins Enable/Inputs are also extended to make connections easier.
The functioning of L293 can be understood through simulation on Proteus Design Suite.This is an expensive Commercial software by Labcenter Electronics.But a Demo version is available for free.The demo version has some limitations on usage of number of pins & the work cannot be saved.
Download the demo version from
The simulation procedure is explained in the video below :