L293 shorting output problem

milos2 · ‎2014-01-23

Posted on January 23, 2014 at 10:12

I use L293 as an buffer and level shifter from 5VDC to 24VDC on two of our boards and it works perfectly except for one thing: shorting any of the outputs to GND kills the chip! Could you suggest me a solution to this problem? If there is a device with similar function and shortcut protection embedded in chip, it can also be a solution to the problem.

I tried to implement a circuit suggested in ST's application note http://www.st.com/st-web-ui/static/active/cn/resource/technical/document/application_note/CD00003776.pdf

without success. L293's outputs and GND are connected to board's connector. When I make shortcut between one of the outputs and GND pin on connector, shortcut protection works ok. However, when I connect leads (2m long lead for output signal and 2m long lead for GND) and make shortcut at the end of leads, I kill L293.

Regards,

Milos Stankovic

Enrico Poli · ‎2014-01-27

Posted on January 27, 2014 at 15:46

The L293 is not designed to provide short circuit protection and the solution described in the AN introduce a strong delay between the short circuit event and the turn-off of the output.

I suggest you to take a look to the Intelligent power switches:

http://www.st.com/web/en/catalog/sense_power/FM142/CL1499

milos2 · ‎2014-02-07

Posted on February 07, 2014 at 10:24

Thanks! I will have a look.

Regards,

Milos