INDEX

L298
Stepper motor driving with ULN2003
Stepper motor diriving with L293D
Another  motor driving circuit
 

L293D

The most commonly used H-bridges are L293D and L298. L293 have maximum current rating of 600mA while that of L298 is 2A. L293B and L293D are available in market. If you use L293B you have to put 4 protection diodes while in L293D, diodes are inside the IC. L298 requires external protection diodes. Let's start with L293D

L293D has two channels. i.e, you can connect two motors to the same bridge. I have driven 4 motors of 250mA using L293D, with 2 motor in each channel. Now let's see the ratings of L293D
Output Current 1 A Per Channel             (600 mA for L293D)
Peak Output Current                            2 A Per Channel (1.2 A for L293D)
Maximum VC – 4.5 to 36V (>VSS)( it should be greater than or equal the supply voltage,vss)
input side                  (input to L293D from parallel port or microcontroller)
VIH                       High-level input voltage( a voltage which L293D takes input as HIGH(1))
VC ≤ 7 V (2.3 to VC)
VC ≥ 7 V (2.3 to 7 V)
VIL                   High-level input voltage( a voltage which L293D takes input as LOW(0))
(-.3 to 1.5V), remember that VIL should not be less than -.3V
output side(output of L293D to motor)
VOH High-level output voltage (VCC2 − 1.8, VCC2 − 1.4)
VOL Low-level output voltage (1.2v , 1.8v)
If you want to use PWM to control L293D then apply PWM output to the chip inhibit of the IC.
Remember all these parameters when you connect L293D in circuits. L293B are available, if you use it use 4 external protection diodes. L293D costs around Rs.90 . I have seen too many post about the problems occurring L293D, so here i am explaining things in more detail, how to connect L293D in circuit so that it won't create any problems to you.