L6205 , PWM

eyals111 · ‎2013-04-18

Posted on April 18, 2013 at 16:45

HI ,

1.can any one tell me how to PWM DC motor using L6205 ,via EN pin or

INX pin ?

2.how can i make the motor coasting (in PWM OFF) ?

for the Table in the Datasheet

when EN=1, if IN1=0,IN2=1 => OUT1=GND OUT2=VS

else IN1=1,IN2=0 = > OUT1=VS OUT=GND

how can i put the H bridge in HighZ (only 1 side ) ?

from what i understand PWM DC motor in specific direction there are 2 phase

PWM ON - the motor get VS (Left H bridge side) and GND (High H bridge side)

PWM OFF - the motor is coasting (Left H bridge side is in High Z) and GND (High H bridge side)

Enrico Poli · ‎2013-04-29

Posted on April 29, 2013 at 11:33

Hello,

For driving a DC motor using the L6205 you need to use the INX inputs to generate the PWM signal. Using the ENX is not recommended because the power stage is turned off during the OFF time (overcurrent protection disabled) and the PWM range is significantly reduced (the system works only up to the 50% of duty-cycle).

The suggested setup is the following (one direction riving):

IN1X <-- PWM

IN2X <-- HIGH

ENX <-- HIGH

In this condition the voltage applied to the motor is Vmotor = VS x (1 - DC) (100% of PWM duty-cycle forces a 0V on the motor and 0% forces the VS).

Using this configuration the overcurrent protection of the device is always active.

Regards

Enrico

gscalegraphics · ‎2013-10-11

Posted on October 11, 2013 at 23:44

The above is very helpful, as I am experiencing these same problems. How can I use PWM in the ''Parallel connnection for higher current'', L6205, Fig 26 of AN1762 App note? I need to drive the motor both directions.

Edit: Just flop IN2 from High to Low I guess?

Enrico Poli · ‎2013-10-14

Posted on October 14, 2013 at 15:34

Hi,

the suggested configuration is the following:

ENA and ENB --> Enable

IN1A and IN1B --> PWM

IN2A and IN2B --> FW\REV

In this case the changing the FW/REV value the motor direction is changed.

Pay attention to the PWM duty-cycle: when FW\REV is LOW a 100% DC corresponds to the maximum speed and 0% DC stops the motor. When FW\REV is HIGH the DC vs. speed relation is reversed (100% --> motor stopped, 0% --> maximum speed).

Regards

Enrico