L293D With PWM

I’m using L293D with two DC 5V motors. I use the two ENABLE inputs feeding from two PWM inputs.PWM frequency = 200Hz.

L293D power from 5V supply.Vcc2 = 6V for motors in L293D.

The problem is I can speed down the motor very few range from PWM signal.

I use 8 bit resolution.

so the maximum speed = 255 duty cycle = 5V

The low range is only 180 duty cycle = 3.5V (not noticeable much)

Below 180 duty cycle the motors won’t work. But the motors will work down to 1V direct power supply.

I guess the enable pin does it have a threshold value??

I've used that device, but not with pwm on the enable, maybe it doesnt have a good response time, if you have a dual channel 'scope, probe the pwm input and what you get across the motor, they should be the same, if not then the 293 isnt happy.