Electronic – L293 VCC1 3.3v


I'm building a wireless motor controller using an atmega328p AVR and Gainspan GS1011M wifi module, both of which are 3.3V devices. I've seen several references to running the L293 H-bridge on 3.3V:


If this is true then I only need one voltage regulator for 3.3V, which would keep the part count and complexity to a minimum. However the datasheet for the L293 lists 4.5V as the minimum for VCC1. Can anyone confirm that the L293 will function at 3.3V, or is there an alternative lower voltage H-bridge?

Best Answer

Someone might tell you that they have operated a particular L293 chip with a VCC1 of 3.3V, but that does not mean another chip (even one from the same manufacturer) will work for you. The datasheet is the binding document, that is what the manufacturer guarantees. Everything else is a gamble. Some people like gambling, some even win occasionally. I hope they don't design life-critical electronics.

But note that the minimum input level for a logic 1 is only 2.3V, so if your controller can provide that you can drive the l293 directly, provided that you feed it a VCC1 within its required limits. I assume you have a higher voltage for the motors, so you can derive 5V from that (or maybe even use it directly).