design of pmos common source with current soure load

[virtuos]

PMOS or NMOS

Is it possible to tell whether a given mos transistor is P-type or N-type just by looking at it:?::?::?::

 

[matbob]

Re: PMOS or NMOS

Hi virtuos,

What do you mean by looking at it? Looking on the device or a circuit symbol?
When connected in a circuit, in most cases(in digital circuits), the NMOS would have its source connected directly to GND and the PMOS would have its source connected directly to Vdd.

 

[Tahmid]

PMOS or NMOS

You look at the part number and look it up in a data book or datasheet and then determine.
Tahmid.

 

[amraldo]

Re: PMOS or NMOS

You look at the part number and look it up in a data book or datasheet and then determine.
Tahmid.

MOS transistors are not discrete components, so you cant look at datasheet or data book for them. They are integrated ones. If you have the schematic, you can know which is NMOS and which is PMOS. They have different symbols. Source of NMOS are usually connected closer to the GND side while those of PMOS are usually connected closer to VCC or VDD side.
--
Amr Ali
www.embedded-tips.blogspot.com

 

[virtuos]

Re: PMOS or NMOS

well thanx for your replies

I was asking that is it possible to tell whether a component is pmos or nmos just by looking......'by looking' i mean just by looking at the components(neither the symbols, nor by connecting them in a circuit)

Actually this was asked in an interview, so I thought there must be a way to distinguish between the two just 'by looking'....:!::!::!:

 

[amraldo]

Re: PMOS or NMOS

PMOS and NMOS are not available as discrete components. So it is a tricky question .
--
Amr Ali

 

[keith1200rs]

Re: PMOS or NMOS

PMOS and NMOS are not available as discrete components.

Of course they are - there are thousands of them available as discrete components.

If you are talking about discrete devices then you can only distinguish one from the other by the part number.

If you are looking at the silicon of an IC you can tell PMOS from NMOS because you would be able to see the Nwell for a PMOS if it is a P type substrate, for example.

Keith

 

[amraldo]

Re: PMOS or NMOS

send me a link of a discrete pmos and nmos then.
--
Amr

 

[keith1200rs]

PMOS or NMOS

www.irf.com

International Rectifier make a few thousand different ones, as do loads of other companies.

Keith

 

[amraldo]

Re: PMOS or NMOS

sounds interesting. first time 2 see it. these discrete ones r only used in power electronics?
--
Amr

 

[keith1200rs]

Re: PMOS or NMOS

sounds interesting. first time 2 see it. these discrete ones r only used in power electronics?
--
Amr

Mostly, but some are smaller e.g. 2N7000. There are also RF ones as well, low power as well as high power. Mitsubishi for example do power RF ones. I cannot remember parts numbers and I have limited internet access at the moment. I can check tomorrow if you want more information. Agilent do HEMT transistors for RF.

Keith.

 

[amraldo]

Re: PMOS or NMOS

r they recent ones?
i mean when was the first discrete mos transistor manufactured?
--
Amr

 

[keith1200rs]

PMOS or NMOS

Siliconix (now part of Vishay) were selling them 25 years ago, at least.

Keith

 

[Audioguru]

PMOS or NMOS

The quiz asked if you can see if a Mos transistor is an N-channel or a P-channel just by looking at it.

Of course you can if you have enough experience to know their spec's from the part number that is printed on them.

The quiz was asking about your experience.

This is a world wide forum. Things in Egypt are different. Very different.

 

[suru]

PMOS or NMOS

BY NUMBER ,U CAN RECOGNISE IF NOT IN CIRCUIT AND SEE THE CONNECTION IF CONNECTED IN CIRUIT.