Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronic Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

how to understan the content from a textbook?

Status
Not open for further replies.

xuexucheng

Full Member level 2
Joined
May 6, 2010
Messages
145
Helped
4
Reputation
8
Reaction score
4
Trophy points
1,298
Activity points
2,352
how to understan the content from a textbook?
It's important to remember our constant theme when we design current mirrors, that is, if we can set both the gate-source and the drain-source voltages of a MOSFET, we set the drain current. Similarly if we can set the drain current and gate-source vlotage, then we set the drain-source voltage.


could any nice guy give some detail explanations.
Examples are very welcome.
 

xuexucheng

Full Member level 2
Joined
May 6, 2010
Messages
145
Helped
4
Reputation
8
Reaction score
4
Trophy points
1,298
Activity points
2,352
It is from R. Jacob Baker's book
"CMOS: Circuit Design, Layout, and Simulation, Third Edition"
 

leo_o2

Advanced Member level 4
Joined
Sep 3, 2004
Messages
1,324
Helped
277
Reputation
556
Reaction score
240
Trophy points
1,343
Location
China
Activity points
5,761
It means drain current depends on both Vgs and Vds for some certain transistor.
 

xuexucheng

Full Member level 2
Joined
May 6, 2010
Messages
145
Helped
4
Reputation
8
Reaction score
4
Trophy points
1,298
Activity points
2,352
It means drain current depends on both Vgs and Vds for some certain transistor.
yes, right
however, this does not explain my question.
 

leo_o2

Advanced Member level 4
Joined
Sep 3, 2004
Messages
1,324
Helped
277
Reputation
556
Reaction score
240
Trophy points
1,343
Location
China
Activity points
5,761
I think the meaning is clear.
I can't understand your confusion.
 

xuexucheng

Full Member level 2
Joined
May 6, 2010
Messages
145
Helped
4
Reputation
8
Reaction score
4
Trophy points
1,298
Activity points
2,352
can any nice guy give other explanation?
 

keith1200rs

Super Moderator
Staff member
Joined
Oct 9, 2009
Messages
10,877
Helped
2,064
Reputation
4,128
Reaction score
1,597
Trophy points
1,403
Location
Yorkshire, UK
Activity points
57,276
If you look at the characteristic curves of a MOSFET they are usually shown as a graph of Vds against Id for different values of Vgs. If you fix any two of those three parameters then there is only on value for the third parameter that will exist i.e. it defines a single point on one curve.

The other way of looking at it is through equations. If you have an equation which defines the device characteristics and it has three variables, if you define two of the variables (i.e. give them a value) then the third variable can now only have one value.

Keith
 
Status
Not open for further replies.
Toggle Sidebar

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top