Go Down

Topic: Anyone know a strong P channel MOSFET (about 40v, 1A, logic level) ? (Read 5502 times) previous topic - next topic

diode

Hi,
Can anyone here think of a good logic level P channel MOSFET that can deal with about 40v, 1A? 
Have been searching the internet for hours and thought to try here..
Thanks!

fungus


Can anyone here think of a good logic level P channel MOSFET that can deal with about 40v, 1A?  


I think most of them can handle that much power. Probably quite a few BJTs, too.

Advanced Arduino

johnwasser

You can do parametric searches at both DigiKey.com and Mopuser.com.

At DigiKey I put in the search term 'logic level mosfet'.

Then clicked on "FETs - Single".

Then under FET Type selected "MOSFET P-Channel"

Under Vdss I selected for 40V,45V,or 50V

You can figure out the rest.
Send Bitcoin tips to: 1G2qoGwMRXx8az71DVP1E81jShxtbSh5Hp
See who has no social life: https://forum.arduino.cc/index.php?action=stats :)

AlxDroidDev

I'd say nearly all of them. It'd be more trouble to find one than CAN'T handle that than one that can.

1A at 40V is nothing for a MOSFET, provided they have a cooling rib.

Here's a brief list from Vishay: http://www.vishay.com/mosfets/p-channel/v-ds-gteq-neg31-v-lteq-neg80-v/
Some of my projects:
Shield for DS1337+, DS1624 and AT24C1024B (RTC, temp & mem): http://forum.arduino.cc/index.php/topic,126197.0.html
CHDK Camera remote shutter (BT, IR, USB): http://forum.arduino.cc/index.php?topic=295377.0

Riva

Don't PM me for help as I will ignore it.

AlxDroidDev

Some of my projects:
Shield for DS1337+, DS1624 and AT24C1024B (RTC, temp & mem): http://forum.arduino.cc/index.php/topic,126197.0.html
CHDK Camera remote shutter (BT, IR, USB): http://forum.arduino.cc/index.php?topic=295377.0

diode

Thanks all! Will look at those resources - there are so many.

Was just wondering if there is one or some that are particularly good / easy to interface / power efficient etc.

(like for example the IRF540 N Channel seems to come recommended as an N Channel)

Reading into it also seems they have become much better over time.

ps. yes the IRF520 is N.

CrossRoads

You are using this as a high side switch device?
To drive from an Arduino pin, you will need NPN or logic level N-channel to pull the P-channel's gate low to turn it on, with pullup resistor to 40V to turn it off.
I posted a circuit yesterdy to do that, for driving a halogen lamp.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

CrossRoads

Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

diode

CrossRoads - I want to connect them to a TLC5940. Am presuming a P channel MOSFET can connect straight to a TLC.

CrossRoads

TLC5940 datasheet says it needs some minimal load to switch properly.
Use a low enough value resistor as the Pullup resistor to 40V to meet that.
The TLC5940 will act as the NPN transistor here.
Have not tried this myself, wire up just 1 MOSFET to start and see  how it works.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

diode

Thanks for your thoughts!
Not sure what you mean with the minimal load?
Haven't got a P channel MOSFET at hand so have to get one and try tomorrow.

sparkylabs

What exactly are you trying to do with the mosfet ? if your switching loads then low side switching is best if possible because N channel devices are cheaper and have better characteristics.

JoeN


What exactly are you trying to do with the mosfet ? if your switching loads then low side switching is best if possible because N channel devices are cheaper and have better characteristics.


But a TLC5940 is already a low-side PWM controller that sinks current.  So for a matrix, as an example, if the columns are cathodes you use the TLC9540 to control the columns.  This leaves you to control the rows (anodes), on the high side.  How do you use N-channel for that?  The general way to solve that from what I have seen is P-channel MOSFETs or maybe darlingtons on the high side to source current.
I will never ask you to do anything that I wouldn't do myself.

sparkylabs

yes in that case it has to be high side. unless the LED's are powered from 5v he needs level shifting too as suggested above

Go Up