I am using both L293D and L298N for controlling the stepper motor NEMA17. It rotates and stop as expected. I am not sure about the usage of Enabling provided by the L293D bridge. In this attached file enter image description here

the pin 1 and 9 are used to enable. I am currently setting high on both these pin always and the motor rotates. I thought that enabling the pins can be controlled dynamically. For example, can I set low on pin 1, when I am not using the Input 1 and 2? I though this way the pins are not always enabled and reduce the heat in the H-Bridge. Please let me know if that works.

  • \$\begingroup\$ I tried doing that but motor is not running. I am not sure whether it is due to the logic or my understanding issue. Thanks. \$\endgroup\$
    – Senthil
    Commented Aug 18, 2016 at 0:33
  • \$\begingroup\$ Heat reduction in crappy L293D: electronics.stackexchange.com/questions/108686/… \$\endgroup\$
    – Andy aka
    Commented Aug 18, 2016 at 9:51

1 Answer 1


When L293d enable pins are low, the outputs are high-impedance ('Z' on the L293D function table).

This means no current is flowing through the motor, and hence that winding is applying no torque.

That may be okay when the motor is at rest, and certainly reduces the power use, and heat dissipation.

Further, it is okay for one of the two stepper motor windings while it is turning.

A pattern for turning a stepper motor is to only energise one winding at any instant. This will use less power and run cooler. However, it will produce less torque.

Summary: Yes, switching one winding off, at any instant, by setting one of the two enables low will be fine, will reduce power and heat. However that will reduce torque.

  • \$\begingroup\$ Thank you for confirmation and good to know about the effect on torque. \$\endgroup\$
    – Senthil
    Commented Aug 18, 2016 at 1:52

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