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Topic: SMD MOSFET to power down my SMD H-Bridge (Read 5 times) previous topic - next topic

SouthernAtHeart

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Alternatively, pick a mosfet with a higher Vgs rating but designed for 5V gate drive, such as TSM2313CX.

...still looking for something at Digikey. I can't get the one you mentioned  at Digikey, and at Mouser it's a non stocked item which you've gotta order 15000 of…
Digikey's filtering system doesn't  have the criteria of Vgs, so I'm having trouble selecting one. Once I find something I'll post my updated schematic.

dc42

Formal verification of safety-critical software, software development, and electronic design and prototyping. See http://www.eschertech.com. Please do not ask for unpaid help via PM, use the forum.

SouthernAtHeart


Perhaps PMV48XP then?


Thanks!  Here's what I came up with...
Is R1 needed? I usually put something like that to make sure the motor is off while the Arduino boots up.
So nothing is needed between the Arduino pin and the gate of the BS1338?
Sure appritiate all the help!

I'll be glad to go this route rather than just a relay.

dc42

R1 is worth including. Its purpose is to ensure the mosfet is kept off when the system is powered up but the Arduino pin has not yet been configured as an output. It isn't needed if the pin feeds a BJT, but then you need a series resistor instead.
Formal verification of safety-critical software, software development, and electronic design and prototyping. See http://www.eschertech.com. Please do not ask for unpaid help via PM, use the forum.

SouthernAtHeart

Quote
Looks OK to me. The Vgs rating of that P-channel mosfet is only 8V, uncomfortablly close to the 6V drive it is getting, so it is probably better to spit the 2K2 resistor into 2 x 1K and drive the gate from the junction of the two. Alternatively, pick a mosfet with a higher Vgs rating but designed for 5V gate drive, such as TSM2313CX.


I have changed from a 6 volt motor supply to a 9 volt supply, (and tapping off 4.5v for the 328 chip), but I don't understand this Vgs thing, so will this schematic still work to turn on/off Vcc to my motor driver chip?
Will I still need to have the 2k2 resister split into 2 1k resistors?  I don't understand thus part.
Thanks.

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