N channel MOSFET Terminal(Source, Gate, Drain,body) Identification

Thread Starter

litun

Joined Sep 19, 2017
14
mosfet.JPG
Dear all, I have a 3 leg H bridge which has 6 mosfets as shown in the picture.
I have numbered each legs of a mosfet as 1,2,3,4. The middle leg(number 2) of the mosfet has been cut and pushed down.
I have found the data sheethttp://www.mouser.com/ds/2/196/Infineon-IPD90N04S4_05-DS-v01_00-en-1226334.pdf
But in the datasheet i do not find which terminal is gate, which terminal is source, which terminal is gate, physically on the mosfet.

Please help me to find the Source, Gate, Drain,body terminals physically on the mosfet !!
 

dl324

Joined Mar 30, 2015
8,913
The pins are numbered 1 to 3 from left to right.

If you didn't have that information, you can use a diode checker to identify source and drain. Assuming the bulk connection is made internally.
 

spinnaker

Joined Oct 29, 2009
7,815
View attachment 141756
Dear all, I have a 3 leg H bridge which has 6 mosfets as shown in the picture.
I have numbered each legs of a mosfet as 1,2,3,4. The middle leg(number 2) of the mosfet has been cut and pushed down.
I have found the data sheethttp://www.mouser.com/ds/2/196/Infineon-IPD90N04S4_05-DS-v01_00-en-1226334.pdf
But in the datasheet i do not find which terminal is gate, which terminal is source, which terminal is gate, physically on the mosfet.

Please help me to find the Source, Gate, Drain,body terminals physically on the mosfet !!

It does tell you but it is not very apparent. It is a TO-252 package. That is mentioned in the datasheet. Any TO-252 pinout diagram would have given you your answer.

upload_2017-12-15_21-41-42.png
 

Audioguru

Joined Dec 20, 2007
11,251
Your TO-252 dimensions drawing does not show gate, source and drain terminals.
Mouser copied maybe only parts or the datasheet but Infineon 's website is down for maintenance now.
 

Externet

Joined Nov 29, 2005
1,410
The gate is always the one using the narrowest trace on the PC board, as carries no current. I can see that is #1.
Source and drain are interchangeable, unless there is a built-in diode added inside the package, which can be detected with a multimeter.
Manufacturers can name the interchangeable source and drain pins to eliminate confusion or subtle preferences for the die.
Or, to identify; the most negative trace is connected to the source terminal.
Typically, pins 2 and 4 are the same.
 
Last edited:

spinnaker

Joined Oct 29, 2009
7,815
Your TO-252 dimensions drawing does not show gate, source and drain terminals.
Mouser copied maybe only parts or the datasheet but Infineon 's website is down for maintenance now.
But it shows pins 1 2 and 3 and those are also shown in the datasheet on the schematic symbol. Not real hard to figure out what is what.

TO-252 can be used for all types of things other that MOFETS. A TO-252 package is a TO-252 package.
 

crutschow

Joined Mar 14, 2008
23,347
Source and drain are interchangeable, unless there is a built-in diode added inside the package,
All MOSFETS have an inherent substrate diode connection.
Typically it is connected to one of the channel terminals, making it the source terminal, but some have the diode brought out to a separate (fourth terminal) so you can bias the substrate independent of the source and drain voltages.
 

Thread Starter

litun

Joined Sep 19, 2017
14
It does tell you but it is not very apparent. It is a TO-252 package. That is mentioned in the datasheet. Any TO-252 pinout diagram would have given you your answer.

View attachment 141758
Thank you for the information about the packaging. Good to know.But I have a question.
Can you explain how to interpret Source,Gate, Drain and Body(Substrate) from a TO-252 package.
 

Thread Starter

litun

Joined Sep 19, 2017
14
Thank you all. So finally to conclude(from the figure in the 1st post)
  • Terminal 2 and 4 are connected and they are the Drain(Supply, 12V)
  • Terminal 3 is the Source(Gnd)
  • Terminal 1 is the Gate
Also according to the following figure:-
https://goo.gl/images/iYfftY
 
Last edited by a moderator:

spinnaker

Joined Oct 29, 2009
7,815
Thank you for the information about the packaging. Good to know.But I have a question.
Can you explain how to interpret Source,Gate, Drain and Body(Substrate) from a TO-252 package.

You answered your own question above. ;)

Yeah all you needed to do was to compare the two above. If you had a link to the full datasheet it might have been less confusing. I don't know why mouser truncates the sheet.
 

Audioguru

Joined Dec 20, 2007
11,251
Infineon's website works today. Their datasheet also does not show which pin is which, maybe they assume you know that the pins are counted 123 left to right, when the pins are downward. Why don't dey say dat?
 

spinnaker

Joined Oct 29, 2009
7,815
Infineon's website works today. Their datasheet also does not show which pin is which, maybe they assume you know that the pins are counted 123 left to right, when the pins are downward. Why don't dey say dat?

Amazing that Infineon is actually to blame. I figured it was just Mouser messing up on copying the datasheet. Infineon indeed makes it confusing. I whole logt more straight forward if they included a drawing of the package.
 

Thread Starter

litun

Joined Sep 19, 2017
14
As all of you know Infineon does very poor documentation, it is really difficult to figure out how to find these terminals.
Further more, I think the Mouser has the full documentation from Infineon. There is no other extra info.

I would like to thank you all for your support. :)

But my second question start here.
I use these mosfets with a Infineon chip and my programing environment is Keil microvision 5.
Earlier I was able to operate the mosfets by the pwm from the Infineon chip for a BLDC motor application. But all of a sudden , one day when i supply PWM pulses to the gates of Mosfets, the error I get(from the debug window of Keil ) that “external FET source–drain short” for all 6 mosfets.
But surprisingly when I check physically with multi-meter the source and drain (leg no 2 and 3) don’t show any short.

How is is possible?

I am in serious doubt whether “Infineon IPD90N04S4-05” Mosfets on the board has been completely failed.
 

shortbus

Joined Sep 30, 2009
6,979
But surprisingly when I check physically with multi-meter the source and drain (leg no 2 and 3) don’t show any short.

How is is possible?
If that is so, wouldn't that lead you back to the actual driver chip as the fail? Or at least that's where I would look next.
 

spinnaker

Joined Oct 29, 2009
7,815
As all of you know Infineon does very poor documentation, it is really difficult to figure out how to find these terminals.
Further more, I think the Mouser has the full documentation from Infineon. There is no other extra info.

I would like to thank you all for your support. :)

But my second question start here.
I use these mosfets with a Infineon chip and my programing environment is Keil microvision 5.
Earlier I was able to operate the mosfets by the pwm from the Infineon chip for a BLDC motor application. But all of a sudden , one day when i supply PWM pulses to the gates of Mosfets, the error I get(from the debug window of Keil ) that “external FET source–drain short” for all 6 mosfets.
But surprisingly when I check physically with multi-meter the source and drain (leg no 2 and 3) don’t show any short.

How is is possible?

I am in serious doubt whether “Infineon IPD90N04S4-05” Mosfets on the board has been completely failed.
Is there a Keil support forum? Might be best to ask that one there. Most people here are Pic or Arduino.

It might just be a software issue. Or they might be able to tell you exactly what the software is looking at and what to check.
 

Thread Starter

litun

Joined Sep 19, 2017
14
No...it is not the failure of driver chip.
If i switch on the PWM, it shows error message "FET over current" along with “external FET source–drain short”.
But physically when i check continuity between source and drain, there is no short.
The circuit diagram as follows.(6 gates are highlighted)
Bridge.JPG
 

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Thread Starter

litun

Joined Sep 19, 2017
14
Is there a Keil support forum? Might be best to ask that one there. Most people here are Pic or Arduino.

It might just be a software issue. Or they might be able to tell you exactly what the software is looking at and what to check.
It's not about any specific programming environment, it's about finding out whether mosfet is fine or short.
please see this post
https://electronics.stackexchange.com/questions/63568/what-can-cause-a-drain-source-short-in-a-fet
 
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