EdsonEletric

modified 6 years ago

CAN Bus Transceiver

335

04:20:10

Circuit that generates CAN High and CAN Low signals for serial differential communication in CAN Bus networks. Zeros and Ones are achieved by calculating CAN H - CAN L. Pussh the button to see  the waveforms (blue and green, CAN High and CAN Low, respectively) at the MOSFETs outputs and the resulting differential signal (orange). 

I tried to approximate the used MOSFETs to commercial ones as I was wisely adviced, but I had no success. The wave form gets very weird. I will study further improvements to achieve this. Thank for all that commented.

published 6 years ago

kiani

6 years ago

Interesting circuit..maybe using bigger mosfets, don't know.

EdsonEletric

6 years ago

Thanks Kiani. What do you mean by bigger MOSFETs? Please help me. I am new with this app's FET.

kiani

6 years ago

The EC mosfets are tiny,,VLSI mosfets,. Only capable of tiny currents....check the misfet library. There are lots of models you can choose from. With vrious max. Vdd and Id, Rds on, etc.

kiani

6 years ago

http://everycircuit.com/circuit/5282567524450304

2ctiby

6 years ago

Choosing a mosfet is just as easy to do by going to a site which supplies Mosfets, such as Vishay.com ... Just copying the datasheet Rds(on) is no use however if your own circuit has a different gate voltage (Vgs), since a circuit Rds(on) changes as per the Vov and whether the Mosfet is in a Saturation or Ohmic state ... The kiani 'library' does not supply the appropriate matching Vgs which is stated on the datasheet, so the kiani library is in effect a waste of time. Once you have obtained the datasheet Vgs and Vgs(th) with its matching Rds(on), then you can calculate its beta and so adjust your circuit Mosfet beta appropriately ... Failing to adjust for the datasheet beta (and lambda in saturation) will mean that your circuit Rds(on) may be considerably different to the real circuit Rds(on), depending on the extent of your Vgs change.

EdsonEletric

6 years ago

Thanks both of you! Your advices were very helpful. I am going to get deeper in mosfets studies.

kiani

6 years ago

[BLOCKED]

2ctiby

6 years ago

http://everycircuit.com/circuit/5031959353622528

PrathikP

6 years ago

@edisoneletric i just want to warn you that @2ctiby is a fraudulent user and must be ignored. There is nothing wrong with @kiani's MOSFET library. I use it myself and can tell you that it's fine. A lot of effort has been put into the library and is as good as it can be on this app.

2ctiby

6 years ago

[BLOCKED]

2ctiby

6 years ago

What is the point of the kiani library, when users still need to go to vishay.com etc to obtain further necessary data ... users may just as well go straight to vishay.com and look for a mosfet there.... Like kiani, Prathik does not understand how or why the EC mosfets need beta adjustment ... they probably don't even know what beta means, or how it relates to Vov ... kiani asked if anyone could help him find how to calculate the current in that previous mentioned link ... you won't find prathik being able to do that, yet still he talks as though he knows mosfets.

2ctiby

6 years ago

@prathik ... Do you know the standard formulae for mosfets? Have you not seen Kn and beta and Vov in them? ... There is no Vov supplied in the kiani library. Are you able to calculate drain current? The answer is NO to all of those ... you know nothing, but talk big.

kiani

6 years ago

@2ctiby you are talking to professional engineers,, stop humiliating yourself,,, why.?!

2ctiby

6 years ago

Lol ... come back when you can calculate your drain current here ... http://everycircuit.com/circuit/5031959353622528

kiani

6 years ago

[BLOCKED]

2ctiby

6 years ago

Incomplete formulae are wrong when it comes to requiring correct results.

kiani

6 years ago

[BLOCKED]

PrathikP

6 years ago

[BLOCKED]

2ctiby

6 years ago

@PrathikP ... If you are stuck on any point in my 'Fun with mosfets' pages, or if you disagree with any point regarding standard mosfet formulae, then state your query clearly and we can discuss each point. So far you have never done that. Answer me straight: Are you able to calculate the drain current in this following kiani presentation whereby you arrive at the seen EC result of 242mA. If not then you need to quietly slip away with your tail between your legs ... http://everycircuit.com/circuit/5031959353622528

PrathikP

6 years ago

"so far you have never done that" it's because there has never been a necessity to do that. Oh and i don't have to prove anything. It's quite clearly who needs to slip away.

PrathikP

6 years ago

Look, you may know all the math formulas in the world, but anybody can memories a bunch of formulas, insert values and come up with a result. It's pretty simple. And that my point. You know all the formulas (or you google it and paste it here) and you seem to have memorised a bunch of formulas (or googled and pasted), but you do not understand any of it. My point exactly. Those 2 links i provided have all the proofs that i need

2ctiby

6 years ago

Just as I thought ... PrathikP does not know how to use Mosfet parameters + Vdd to obtain the drain current, and likewise can not therefore initiate a suitable Vgs in EC which complies with a datasheet beta/Rds(on) ... No more to say really, other than that his use of mosfets is a waste of time and meaningless until he accepts that he needs to learn such things.

2ctiby

6 years ago

If 'in depth' understanding is his concern, then we can discuss how the percentage alteration of the the oxide inversion layer length (L) affects the Vds and drain current and so alters the Rds(on)... which incidentally can be determined here on EC.... and note that the standard mosfet formulae thus include Vds

2ctiby

6 years ago

I am open to sensible polite questions/discussion on any mosfet enquiries... but not to arrogant/insulting replies which only highlight inadequacies with lack of real knowledge.

PrathikP

6 years ago

Like i thought, he just Googles, copies and pastes technical terms

2ctiby

6 years ago

Being able to set mosfets correctly for a circuit, and being able to calculate the drain current etc in a circuit, eg as for that circuit of kiani, is not copy/pasting ... PrathikP is unable to do that and will not face up to it. This is what I have been saying all along: You should not just copy/paste details from a 'kiani library' ... it does not work that way, proper structuring is required instead, including the individual circuit Vov and necessary mosfet beta adjustment for compatibility with the datasheet mosfet ... That is why EC mosfets have settings for us to use.

kiani

6 years ago

So far @2ctiby talks and talks and talks again..never any actions....like his counter partner lenny,, just talk, talk and talk.... Mosfet talk...his have fun with mosfet rubbish talk, and talk.... 2ctiby modeled 1 mosfet and it was a disaster,,, he does not understand any electronics in practice.....where is one model he has offered EC.!?

kiani

6 years ago

Where is one model 2ctiby has offered EC.!?

kiani

6 years ago

Where!

kiani

6 years ago

[BLOCKED]

2ctiby

6 years ago

I offered to show kiani the complete outline of how to obtain his requested drain current including all the formulae ... but look at his response. Does he really think that I will perform for him whilst he continues to abuse, lie, and place insults on all of my presentations? I know how to use the correct formulae, he does not. He vastly needs to change his attitude before I consider offering any help.

kiani

6 years ago

The drain current post, was is an exercise for you or anybody interested.. I don't need your help.. ..

2ctiby

6 years ago

@kiani ... Fine... No help for you then as per your request, but other users should be aware that your recent production with a Pmos FQP27P06 has a datasheet ''Absolute maximum' value stated as being |25v| for the Vgs ... whereas you are applying far more Vgs there as seen. (place a volt meter across the gate and source). Your mosfet is in place back to front, you have applied a Vgd of |10v| instead of applying a Vgs of |10v| ... That necessary information is found on datasheets but not in your mosfet 'library'.

kiani

6 years ago

[BLOCKED]

kiani

6 years ago

[BLOCKED]

kiani

6 years ago

[BLOCKED]

EdsonEletric

6 years ago

You two are excellent and smart guys! You don't have to hate each other. Join efforts and help people like me, who doesn't know everything. Please don't fight! You are great people! Forgive one another.

kiani

6 years ago

[BLOCKED]

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