hspice

Seer Akademi Pvt. Ltd., 2012 Seer Akademi Confidential

HSPICE


INTRODUCTION TO HSPICE

For simulating digital circuits we use HDL's and Simulation tools like

VCS,CVER,MODELSIM,XILINKs etc.

For Simulating simple RLC ,Diode, etc. we are using manual

analysis.

Manual analysis of that circuits may not give more accurate readings

because we have to take all diode parameters including second order

effects into account.

Computer aided simulation is necessary.

HSPICE is a circuit simulator used to simulate analog circuits

having the components R,L,C, active devices etc.


HISTORY

HSPICE is a analog circuit simulator from Synopsys tool.

HSPICE tool having 2 versions namely 1)HSPICE 2)HSPICE RF

HSPICE is used to simulate having the device frequencies in the

range DC to Microwave frequencies.

HSPICE RF is used to simulate the Radio Frequency devices .

HSPICE developed using Fortran Based script.

HSPICE RF developed using C++ Based script.


WHAT IS HSPICE?

HSPICE is a program that takes in a netlist.

HSPICE net list is simple text file having .SP extension.

The netlist contain

a)circuit description

b)analysis options

c)output the analysis

First line of HSPICE is comment.

Circuit topology tell how the nets are connected.

Analysis parts tells which analysis you want to do like AC analysis ,DC

analysis, Transient Analysis ,Transfer Function Analysis.

Output Analysis is used to print, plot the analysis results.

Last line netlist .end command.


MECHANICS OF WRITING A HSPICE

NETLIST

HSPICE netlist is a case insensitive

First line of a hspice netlist is always a comments

You can write the comments at any place in the netlist by using *

Last line of a hspice netlist is .end which tells hspice netlist to terminate

the program.


DECLARATION OF PASSIVE ELEMENTS

CAPACITOR:

C{name} {node+} {node-} [{model}] {value} [{IC=initial}]

Examples : C 1 2 10pf

CLOAD 2 2 4 CMOD 20pf IC=1.5v

INDUCTOR:

L{name} {node+} {node-} [{model}] {value} [{IC=initial}]

Examples :L 1 2 20mH

LVALUE 2 3 2uH IC=1.2mA

RESISTER:

R{name} {node+} {node-} [{model}] {value}

Example: R 2 3 10k


For the above R,L,C components we have a flexibility to write

-ve and +ve node interchangeable. Because they are bilateral

elements.


DECLARATION OF ACTIVE COMPONENTS

DIODE:

D{name} {node+} {node-} {model} [AREA]

Examples : DCLAMP 4 5 DMOD

BJT:

B{name} {collector} {base} {emitter} [{sub}] {model} [{area}]

Examples :M1 4 6 8 PNPNOM

M2 5 7 9 1 NPNSTRONG 1.5


JFET:

J{name} {drain} {gate} {source} {model} [{area}]

Examples :JI 2 5 0 JFAST

MOSFET:

M{name} {drain} {gate} {source} {substrate} {model} [L={}] [w={}]

Examples :M1 14 2 13 0 PNOM L=25u w=12u

M2 15 3 24 0 PSTRONG


DECLARATION OF SOURCES

CURRENT SOURCE:

I{name} {node+} {node-} [[dc] {value}] [ac {mag} [{phase}]]

Examples :IBIAS 13 0 2.3mA

IAC 2 3 AC .001mA

IPULSE 1 0 PULSE(-1mA 1mA 2ns 2ns 2ns 50ns 100ns)

I3 26 77 AC 1 SIN(.002 .002 1.5MEG)

VOLTAGE SOURCES:

V{name} {node+} {node-} [[dc] {value}] [ac {mag} [{phase}]]

Examples :VBIAS 13 0 2.3mV

VAC 2 3 AC .001mV

VPULSE 1 0 PULSE(-1mV 1mV 2ns 2ns 2ns 50ns 100ns)


DECLARATION OF DIFFERENT INPUT SOURCES LIKE PWL,EXP,PULSE

SINWAVE:

SIN( {voffset} {vpeak} {freq} {tdelay} {damp_factor} {phase} )

PIECE WISE LINEAR:

PWL( {time1} {v1} {time2} {v2} ... {time3} {v3} )

PULSE:

PULSE( {v1} {v2} {tdelay} {trise} {tfall} {width} {period} )

EXPONENTIAL:

EXP( {v1} {v2} {trise_delay} {tau_rise} {tfall_delay} {tau_fall) )


DECLARATION OF ANALYSIS LIKE

AC,DC,TRANSIENT

AC ANALYSIS:

AC [LIN][OCT][DEC] {points} {start} {end}

Examples:

.AC LIN 101 10Hz 200Hz

.AC DEC 20 1MEG 100MEG

DC ANAYSIS:

DC [LIN] {varname} {start} {end} {incr}

.DC [OCT][DEC] {varname} {start} {end} {points}

Examples:

.DC VIN -.25 .25 .05

.DC LIN I2 5mA -2mA 0.1mA VCE 10V 15V 1V


TRANSIENT ANALYSIS:

.TRAN {print step value} {final time} [{no print time} [{step ceiling value}]] [UIC]

Examples: .TRAN 5NS 100NS

PLOT ANALYSIS :Plot Output.

.PLOT [DC][AC][NOISE][TRAN] [ [{output variable}*]

Examples:

.PLOT DC V(3) V(2,3) V(R1) I(VIN)

.PLOT AC VM(2) VP(2) VG(2)


PRINT OUTPUT:

.PRINT [DC][AC][NOISE][TRAN] [{output variable}*]

Examples:

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

.PRINT AC VM(2) VP(2) VG(5) II(7)

PROBE :probe command is used to save the simulation output what you

specified in the statement.

.PROBE [output variable]*

Examples: .PROBE

.PROBE V(3) VM(2) I(VIN)


USE OF OPTION POST IN THE HSPICE NETLIST

It enable storing of simulation results for analysis

If we put POST=1 save the results in binary

POST=2 save the results in ASCII POST=3

save the results in new wave binary format

Set the option POST and use >PROBE statement to specify which

data you want to save

Nomod option suppresses the printing of model parameters

Finally last line of a netlist is .end


SOME IMPORTANT NOTES FOR WRITTING HSPICE

NETLIST

Ground is a special node in the circuit. So only use gnd or 0 to

specify the ground.

Make sure that proper declaration of +Ve and Ve terminal of a

unilateral elements is like active elements and sources is necessary.

Don't care about bilateral elements whether which is +Ve and -Ve

While declaring voltage source VS

vs vs gnd 10v

we gave source name and node name sameness will not cause any

ambiguities.


TRANSIENT ANALYSIS OF SIMPLE RC CIRCUIT

Hspice netlist for simple RC circuit

1 EE105 SPICE Tutorial Example 1 - Simple RC Circuit

2 vs vs gnd PWL(0s 0V 5ms 0V 5.001ms 5V 10ms 5V)

3 r1 vs vo 1k

4 c1 vo gnd 1uF

5 .tran 0.01ms 10ms

6 .option post=2 nomod

7 .end


AC ANALYSIS OF RC CIRCUIT

1 EE105 SPICE Tutorial Example 4 - Simple RC High-Pass Filter

2 vs vs gnd ac 1V

3 c1 vs vo 1nF

4 r1 vo gnd 1k

5 .ac dec 500 100 1G

6 .option post=2

7 .end


DC ANALYSIS OF A DIODE

1 EE105 SPICE Tutorial Example 3 - Simple Diode Circuit

2.model tut_diode d (is=1e-14 vj=0.6 rs=10)

3 vs vs gnd 5V

4 rs vs vd 5k

5 d1 vd gnd tut_diode

6.dc vs 0V 5V 0.01V

7 .option post=2

8 .end


OPERATING POINT ANALYSIS OF DIODE

.op command is used to find the quiescent point of a diode.

1 EE105 SPICE Tutorial Example 3 - Simple Diode Circuit

2 .model tut_diode d (is=1e-14 vj=0.6 rs=10)

3 vs vs gnd 5V

4 rs vs vd 5k

5 d1 vd gnd tut_diode

6 .op

7 .end


POLE-ZERO ANALYSIS OF A HIGH PASS CIRCUIT

EE105 SPICE Tutorial Example 6 - Pole-zero analysis of a high-pass filter

vs vs gnd ac 1V

c1 vs vo 1nF

r1 vo gnd 1k

.pz v(vo) vs

.end


TRANSFER FUNCTION OF A CIRCUIT

For a given resistive circuit we can find the transfer function by using .tf

command.

you can hand-calculate the answer and compare it to the result you get in

HSPICE

.tf v(v0) vs


HOW TO RUN A HSPICE TOOL

Connect to a server by username and password.

Open a file with .sp extension by using following command.

vim filename.sp and press enter u will see a page.

Type the hspice netlist in page . after typing the netlist save the

program and exit by the following command.

Press Esc and :wq! and enter

To run the netlist type the following command.

hspice filename.sp

After running the netlist it will show the output like this

hspice job concluded


From this output we can know how many active , passive ,unilateral ,

bilateral elements the circuit have and it also shows calculated outputs.

To see the outputs graphically we need to invoke COSMOSCOPE tool.

To invoke this type cscope and press enter.

After this cscope window is opened. In that window click on File

openplotfiles

It will give Voltages and Currents at all nodes..


THANK YOU..

hspice

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