Using PWM to speed down a DC motor

[macbook]

Hi,
I want to use PWM signal to control the speed of my DC motor interfacing with an L293D motor driver....
I want to know how can this be done? Shud the PWM signal be fed into the enable pins of l293d? and what shud be the period of the PWM for proper running of the motors.
Thank you.

[blackbeard]

it's really easy. send the pwm signals through the desired input.. just stick all the enable pins to vcc if you're using the whole chip.

[Soeren]

Hi,

Shud the PWM signal be fed into the enable pins of l293d?

No, the input pins are a better choice, as the enable pins are a bit slower.

and what shud be the period of the PWM for proper running of the motors.

The best (most efficient) frequency depends on the motors, but somewhere around 2kHz to 5kHz will work.