Review Details

L293 L293D Push-Pull 4-Channel Driver IC

Product Rating:

Product Rating
Price
80%
Quality
80%
Value
80%

Product Review (submitted on October 1, 2013):

I'm using this to drive an ultrasonic transducer for distance measuring applications in a single-supply system. It works very well, though I have had some issues (which I have not replicated). I wonder if I would have been better off with the version without internal diodes.

In my test circuit I had a 555 timer driving a 74LS14 driving the control pins of the L293D. Almost immediately I noticed what appeared to be feed-through between the 5V logic supply and the 10V output driver supply. This was apparent from the voltage readings on my good-quality linear bench supply changing without me adjusting the knobs. Eventually, when I was connecting the output driver supply via a jumper wire while the system was live, the chip shorted out. If I applied power to the output driver side of the chip, it was shorted, though the rest of the chip did function. It seems to me that either latch-up occurred and caused damage or a protection diode either on the power supply pins or the driver output pins shorted. The latter theory is why I'd opt for the L293 "sans D" in the future, if possible. I plan to revisit this circuit very soon.

I think I probably just had bad luck and I do like this IC. In general, besides motor driving applications, it's also useful for driving higher effective voltages to a device in low-voltage systems. This way, from a 5V supply, I can get an effective 10V swing on my transducer.