What is the difference between IRL3705N and IRL3705Z?
You have not said what load you will be controlling (ie how many amps of current). Since you will be using 3.3 volt control logic the N option seems appropriate. 20 volts is not a problem as both options can handle up to 55 volts. As for the gate resistors, see the picture for reference.
From 150mA to 2.5-3A
No problem. Also, the transistor has a very low on-resistance and you won't need a heatsink with this package (TO220). However, if you are going to use PWM control at a high enough frequency, you may need to use a heatsink and/or gate driver.
I think 8 bits and 16 bits of PWM are not very big, right? And the same lack of problems for 3A, 15-20v and uselessness of TO220 in the Irlb3034 series mosfets and the IRL3705N transistor?
This is PWM resolution, not frequency. The IRLB3034 is overpowered for the purpose and its gate capacitance is quite large, which can lead to potential problems even at low PWM frequency if no driver is used.
Thank you very much! Then how can I understand, depending on the frequency, at what limit the suitable mosfets start, for example, for 80Hz, 1kHz, 64kHz, etc.?
I would say everything is different. All you have to do is look at the data sheet.
Neither can be controlled by 3.3V.
You need a MOSFET with a maximum Rds(on) specified at a gate voltage of 3.3V or less.
Doesn't the datasheet for these three MOSFETs say they are capable of handling 3.3v in a gate to source diagram?
They are not usable at 3.3V so it does not matter.
What three? You only gave two, N and Z.
No, the datasheets for the N and Z give no such specification.
I made a working circuit with 9V battery, 500mA motor and IRL3705Z, the only one thing is heating - IMS1117:
*I was just too lazy to get out the Arduino Nano, it’s not connected to anything.
I also mentioned IRLB3004 in disscusion
Doesn't seem to be a valid part number.
You are right I made a mistake: IRLB3034
Still no Rds(on) specification at 3.3V or less.
You need to find another MOSFET.
For example, irlb3034 does not even heat up even under a 100A current when operating from 3.3 V, but such transistors must be inferior in some way to those that only output 5A (IRL3705Z) from 3.3v and those that start operating only from 10V?
It appears to have an Rds(on) of 1.6 milliohms at 4.5v. https://www.infineon.com/dgdl/irlb3034pbf.pdf?fileId=5546d462533600a40153566027b22585
100Amps should cause it to dissipate 16 watts.
