As you can see in attached image where 7408 is used to drive mosfets.
I want to use L293 (instead of 7408) to drive 4 power mosfets (with more than 10v to gate) for unipolar stepper motor. Because 7408 still can only provide max 5.25V to Mosfet Gates that is still low volts to make mosfets on fully.
Can I use L293 as I want? If not then what is better option or method to use in this circuit.
Thanks
Here's one quad low-side MOSFET driver chip, in DIP package:
That'll handle even monsterously large MOSFETs easily, just give it 12V and lots of ceramic decoupling
(several uF at least).
(The L293 cannot work as a gate driver, it doesn't drive down to 0V to switch them
properly off due to the darlington outputs. Standard MOSFET drivers use smaller
MOSFETs internally to get rail-to-rail output drive).
Thanks for reply. Please check attached file, I did some work to use TC4468-69. Is it right way to use them.
Is it really important to use 1uf and 0.1 uf capacitors in series with +V?
Can I use co-amplifier (single-741, Dual-LM833, Quad-LM3900) instead of TC4468-69 in my unipolar stepper driver application?
Yes that looks resonable - the dual inputs are a nice feature for flexible enabling as you deduced.
More ceramic decoupling, plastic film isn't going to cut it at the speed involved unless its a low
inductance type (non-wound) - I think this means you need 1206 or so SMT capacitors really - these are
available upto and beyond 10uF in ceramic nowadays.
The decoupling layout should be tight, as should the wiring to the MOSFET gates, stray inductance
matters in this sort of setup due to the very high dI/dt values.
I got your point.
What about the use of co-amplifier with L297 to drive Mosfets in above circuit? Because, possibly, TC4468-69 may not be available in my local market (I did not confirm yet).
Thanks
