Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics 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

simulating Current-controlled current source...

Status
Not open for further replies.
always@smart

always@smart

Full Member level 4
Joined
Feb 8, 2002
Messages
195
Helped
15
Reputation
30
Reaction score
7
Trophy points
1,298
Location
ASIA
Activity points
2,027
Dear All,

I've tried to simulate a current-controlled current source(CCCS) in Hspice. Refer to the diagram, and the syntax for CCCS is:

Fcccs1 Iout gnd Vsen 0.5
Vsen A gnd 0

My question is : Vsen voltage souce should be 0v or 0.5v (1/2 of the 1v), why?


Thanks in advance...


regards,
smart
 

always@smart said:
Dear All,

I've tried to simulate a current-controlled current source(CCCS) in Hspice. Refer to the diagram, and the syntax for CCCS is:

Fcccs1 Iout gnd Vsen 0.5
Vsen A gnd 0

My question is : Vsen voltage souce should be 0v or 0.5v (1/2 of the 1v), why?


Thanks in advance...


regards,
smart
Click to expand...

First of all, you cannot sense the current at node A, because it is not a current source, the current at that point is depend on the voltage across the resistor.
As we know, current source does not depend on voltage across it. So, from the diagram, it is not a current control current source. This is what i think...
 

    always@smart

    always@smart

    Points: 2
    Helpful Answer Positive Rating
Dear friend,
When you want to sense current thro' any branch in a circuit you
are suppose to add a voltage source with "0v" as an ammeter. This is
fundamental principles of Spice!
So in ur case you need to insert a voltage source of 0v at point A.

ur code will get modified as

R1 vcc A 1k
R2 B gnd 1k
Vsen A B 0v
Fcccs1 Iout gnd Vsen 0.5

Hope this helps ...
 

    always@smart

    always@smart

    Points: 2
    Helpful Answer Positive Rating
Dear all,

i have made a complete netlist :


R1 vcc A 1k
R2 A gnd 1k
Vsen A gnd 0v
Fcccs1 Iout gnd Vsen 0.5

.print i(fcccs1)

vcc vcc gnd 1
rout vcc iout 1k
.trans 10n 100n
.end

For the above netlist, i got i(vsen)=1mA , (fcccs1)= 500uA. However I thought i(vsen) supposed to be 1/(1k+1k)=500uA? So I think the Vsen (dummy voltage according to spice manual) will effect the circuit current. Right?

I want to design a CCCS which will not effect by the Vsen, how?

regards,
smart
 

Dear Friend,
Check with the folloeing netlist!!!
You will get what you are looking for!

R1 vcc A 1k
R2 B gnd 1k
Vsen A B 0v
Fcccs1 Iout gnd Vsen 0.5

.print i(fcccs1)

vcc vcc gnd 1
rout vcc iout 1k
.trans 10n 100n
.end



Whatever result you are getting are right!!!
the current in ur netlist thro' Vsen is = 1v/1k = 1ma
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top