What heatsink should I use for an L298?

[alonyud]

My system data are:
I have 6 dc motor(12V and max 2A)
my duty cycle is change but the T is 1ms
(How do I calculate the power dissipation ?)

 

[MrAl]

Hi,

You would look for the voltage drop of the internal transistors at your specified current, multiply that voltage times that current, then multiply by the duty cycle. Do this for all the transistors that can turn on in the package and then add the results.
For example, if one transistor turns on for 20 percent of the time then the average power is:
P=V*I*0.20
If there is another transistor in series with that one then you have to do that transistor too, and it probably has a slightly different voltage.

 

[Ubergeek63]

you should just switch to a low drop FET based chip

 

[dr pepper]

It depends on various factors, sounds like your base freq is 1kc, you say your motor is 12v at max 2amps, well there could be a big difference if the motor runs for a short time, or spends a lot of time unloaded than operating at full current all the time.
To get an accurate calculation you'd have to factor the average current of the motor.
For a one off I'd start with something like a 1 or 2 degree c per watt sink and go from there.

 

[alonyud]

Thank you