L6205: smoke and flash

[marcosarti29]

Posted on June 05, 2007 at 07:59

L6205: smoke and flash

[marcosarti29]

Posted on May 17, 2011 at 10:14

Hi,

I use L6205 for my application: it drive 2 motors, PWM40KHz, 28V/2A. I must plus power: I have insert 2 L6205 in parallel configuration:

http://digilander.libero.it/ciccio.unico/schema.jpg

My application run for 30 minuts and after...one driver crash (smoke and flash, distructive!!!). Question: I have wrong the parallel connection? I have try also to insert R of 100K and C of 5.6nF between pin microcontroller and driver:

http://digilander.libero.it/ciccio.unico/schema2.jpg

I have same result! Thanks for your help!

[marcosarti29]

Posted on May 17, 2011 at 10:14

Upgrade:

the motor absorb 7.5A (and NOT 2A). I have insert C at 68nf and R at 100K (before the C was 5.6nF) in this configuration: http://digilander.libero.it/ciccio.unico/schema2.jpg this is the enable when the motor absorb 7.5A:(green line) http://digilander.libero.it/ciccio.unico/D003.jpg This is the driver....: http://digilander.libero.it/ciccio.unico/DSC0.jpg :-[ I suppose it's protected from overcurrent and over-thermal but it's not protected from both effect! True? It's possible? Thanks for advice and help!

[vincenzo1]

Posted on May 17, 2011 at 10:14Hello, Since the driver gets damaged after some time and not immediately, it looks like to be an effect of high current/temperature. Try using 5.6nF instead of 68nF on EN pins. This should lower the r.m.s. value of the motor (and driver) current during the overload (the maximum r.m.s. current in paralleled configuration is 5.6A and). Overcurrent threshold is at about 11.2A. Care should be taken to avoid electrical overstress of the IC pins (especially SENSE and OUT ones) as well, which might be due to parasitic inductances on pcb traces causing voltage spikes. Please also refer to AN1762 on st.com. Kind regards Vincenzo Marano