PSpice.pdf

1 BITS-GOA EEE/instr F341 Anita Agrawal

PSpice


Overview

PSpice

Simulation Program with Integrated

Circuit Emphasis


.cir

File

User CKT

Definition

file

.sch

File

User schematic

file

SPICE

Compile

and

RUN

.op

Text file

.print

Text file

.plot

Text file

.probe

Graphics file


B GaAs MES field-effect transistor

C Capacitor

D Diode

J Junction field-effect transistor

K Mutual inductors (transformer)

L Inductor

M MOS field-effect transistor

Q Bipolar junction transistor

R Resistor

T Transmission line

E Voltage-controlled voltage source

F Current-controlled current source

G Voltage-controlled current source

H Current-controlled voltage source

I Independent current source

V Independent voltage source

S Voltage-controlled switch

W Current-controlled switch

Components Source

Switch

Circuit Elements


FORMAT OF CIRCUIT FILES

Title

Circuit description

Analysis description

Output description

.END (end -of-file statement)

File

.CIR extension


Notes

1. The first line is the title line, and it may contain any type of text.

2. The last line must be the .END command. 3. A continuation line is identified by a plus sign

(+) in the first column of the next line. The continuation lines must follow one another in the proper order.


4. A comment line may be included anywhere,

preceded by a semicolon ;

5. The number of blanks between items is not

significant (except in the title line). Tabs and

commas are equivalent to blanks.

Notes contd……


6. PSpice statements or comments can be in either upper- or lowercase

7. SPICE / PSpice is user-friendly software; it gives an error message in the output file that identifies a problem.

8. The symbols in PSpice are represented without subscripts.

Notes contd……


Types of Analysis

• DC Analysis

• Transient Analysis

• AC Analysis

Example: Compute the node voltages and source currents

Independent DC Voltage source

Independent DC current source 0


VS 1 0 DC 20V

R1 1 2 500

R2 2 5 800

R3 2 3 1K

R4 4 0 200

VX 3 0 DC 0V

VY 5 4 DC 0V

IDC 0 4 DC 50m

.end

Code and output

VS 1 0 DC 20V R1 2 1 500 R2 5 2 800 R3 3 2 1K R4 0 4 200 VX 3 0 DC 0V VY 5 4 DC 0V IDC 0 4 DC 50m .op .end

NODE VOLTAGE ( 1) 20.0000 ( 2) 12.5000 ( 3) 0.0000 ( 4) 10.5000 ( 5) 10.5000

VOLTAGE SOURCE CURRENTS NAME CURRENT VS -1.500E-02 VX -1.250E-02 VY -2.500E-03

TOTAL POWER DISSIPATION 3.00E-01 WATTS


.TF (transfer) • Purpose: causes the DC gain to be calculated by

linearizing the circuit around the bias point.

.TF <output variable> <input source name>

e.g.

.TF V(5) VIN

.TF I(VDRIV) ICNTRL

In our Case:

.TF V(4) Vs


Code and output

VS 1 0 DC 20V R1 2 1 500 R2 5 2 800 R3 3 2 1K R4 0 4 200 VX 3 0 DC 0V VY 5 4 DC 0V IDC 0 4 DC 50m .end

NODE VOLTAGE ( 1) 20.0000 ( 2) 12.5000 ( 3) 0.0000 ( 4) 10.5000 ( 5) 10.5000



.TF V(4) Vs

.end

**** SMALL-SIGNAL CHARACTERISTICS V(4)/VS = 1.000E-01 INPUT RESISTANCE AT VS = 1.000E+03 OUTPUT RESISTANCE AT V(4) = 1.700E+02


Voltage Controlled Voltage Source E

Voltage Controlled Current Source G

Current Controlled Current Source F

Current Controlled Voltage Source H

Dependent Sources


Voltage Controlled (Dependent) Voltage Source (E)

1. The first letter of the part

name for the voltage

dependent voltage source

is "E."

2. Positive terminal is

designated as "n+" and

negative terminal is

designated as "n-."

Ebar 17 8 42 18 24.0; gain is 24

efix 3 1 11 0 20.0

efix 3 1 0 11 -20.0; same as above

efix 1 3 11 0 -20.0; same as above

efix 1 3 0 11 20.0; same as above

Ellen 12 0 20 41 16.0

*Name n+ n- nc+ nc- gain


Voltage Controlled (Dependent) Current Source (G)

1. The first letter of the part name

for the voltage-controlled

dependent current source is "G."

2. A current equal to γ times vx

flows from node "n+" through the

source and out of node "n-." γ is

called the transconductance

*Name n+ n- nc+ nc- transconductance

Glab 23 17 8 3 2.5

G1 12 9 1 0 4E-2

Grad 19 40 6 99 0.65

Grad 19 40 99 6 -0.65 ; same as above

Grad 40 19 99 6 0.65 ; etc.


Current Controlled (Dependent)Voltage Source (H)

*Name n+ n- Vmonitor transresistance

Hvx 20 12 Vhx 50.0

Vhx 80 76 DC 0V ; controls Hvx

Hab 10 0 V20 75.0

V20 15 5 DC 0V ; controls Hab

HAL 20 99 Vuse 10.0

Vuse 3 5 DC 20V ; actual voltage source

The first letter of the

part name for the

current-controlled

dependent

voltage source is "H."


Current Controlled (Dependent) Current Source (F)

*Name n+ n- Vmonitor Gain

Ftrn 81 19 Vclt 50.0

Vclt 23 12 DC 0V ; controls Ftrn

Fcur 63 48 Vx 20.0

Vx 33 71 DC 0V ; controls Fcur

F3 2 0 V1 15.0

V1 3 1 DC 0V ; controls F3

The first letter in the part

name for this dependent

source is "F."


Thévenin Equivalent Circuit

• Using PSpice to find Thévenin Equivalent Circuit

• The PSpice "dot command" that makes this easy, is ".TF," where "TF" indicates "transfer function."

• The transfer function is intended to find the ratio between a source voltage or current, and a resulting voltage difference or branch current


.TF (transfer) • Purpose The .TF command/statement causes the

DC gain to be calculated by linearizing the circuit

around the bias point.

.TF <output variable> <input source name>

e.g.

.TF V(5) VIN

.TF I(VDRIV) ICNTRL

In our Case:

.TF V(1,0) Vs

The results of the .TF command are only available in the output file. They

cannot be viewed in Probe.


Vs 2 5 DC 100V

Vc 2 3 DC 0V; controls Fx

Fx 6 7 Vc 4.0; gain = 4

* n+ n- NC+ NC- gain

Ex 2 1 5 4 3.0; gain = 3

R1 3 4 5.0

R2 4 7 5.0

R3 5 4 4.0

R4 7 0 4.8

R5 5 6 1.0

R10 1 0 1MEG

* out_var input_source

.TF V(1,0) Vs

.END

Transfer function = V(1,0) / Vs


NODE VOLTAGE NODE VOLTAGE NODE VOLTAGE NODE VOLTAGE

( 1) 180.0000 ( 2) -60.0010 ( 3) -60.0010 ( 4) -80.0010

( 5) -160.0000 ( 6) -176.0000 ( 7)-864.0E-06

VOLTAGE SOURCE CURRENTS NAME CURRENT

Vs -4.000E+00

Vc 4.000E+00

TOTAL POWER DISSIPATION 4.00E+02 WATTS

**** SMALL-SIGNAL CHARACTERISTICS

V(1,0)/Vs = 1.800E+00

INPUT RESISTANCE AT Vs = 2.500E+01

OUTPUT RESISTANCE AT V(1,0) = 5.000E+00

Output from file

29 BITS-GOA EEE/instr F341 Anita Agrawal 2/2/2016

.DC LIN

•General form

.DC [LIN] <sweep variable name> + <start value> <end

value> <increment value> +<nested sweep specification>

•Examples

.DC VIN -.25 .25 .05

.DC LIN I2 5mA -2mA 0.1mA

.DC VCE 0V 10V .5V IB 0mA 1mA 50uA


.DC DEC /. DC OCT

• General form

.DC <logarithmic sweep type> <sweep variable name> +

<start value> <end value> <points value>

+ [nested sweep specification]

• Examples

.DC DEC NPN QFAST(IS) 1E-18 1E-14 5


.PRINT

• General form

.PRINT <analysis type> [output variable]*

• Examples

.PRINT DC V(3) V(2,3) V(R1) I(VIN) I(R2) IB(Q13)

VBE(Q13)

.PRINT AC VM(2) VP(2) VM(3,4) VG(5) VDB(5) IR(6)

II(7)

.PRINT TRAN V(3) V(2,3) ID(M2) I(VCC)


Previous Example

.dc VS list 10 15 20

.print DC I(r1) i(r2) I(r3) i(r4)

.end


Code and output

VS 1 0 DC 20V R1 2 1 500 R2 5 2 800 R3 3 2 1K R4 0 4 200 VX 3 0 DC 0V VY 5 4 DC 0V IDC 0 4 DC 50m .end

NODE VOLTAGE ( 1) 20.0000 ( 2) 12.5000 ( 3) 0.0000 ( 4) 10.5000 ( 5) 10.5000



.dc VS list 10 15 20

.print DC I(r1) i(r2) I(r3) i(r4)

.end

VS I(r1) I(r2) I(r3) I(r4) 1.000E+01 -5.000E-03 2.500E-03 -7.500E-03 -4.750E-02 1.500E+01 -1.000E-02 -1.500E-12 -1.000E-02 -5.000E-02 2.000E+01 -1.500E-02 -2.500E-03 -1.250E-02 -5.250E-02


.PROBE

• General form

.PROBE [output variable]*

• Examples

.PROBE V(3) V(2,3) V(R1) I(VIN) I(R2) IB(Q13)

VBE(Q13)

.PROBE D(QBAR)


.PLOT

• General form .PLOT <analysis type> [output variable]*

+ ( [<lower limit value> , <upper limit value>] )*

• Examples .PLOT DC V(3) V(2,3) V(R1) I(VIN) I(R2) IB(Q13)

VBE(Q13)

.PLOT AC VM(2) VP(2) VM(3,4) VG(5) VDB(5) IR(D4)

.PLOT TRAN V(3) V(2,3) (0,5V) ID(M2) I(VCC) (-

50mA,50mA)


.OP

• Helps to give more details about the bias points in

the output file

PSpice.pdf

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