s-edit manual

7/30/2019 S-edit manual

1/69Nitte Meenakshi Institute of Technology Page

Dept. of E&CEVLSI LAB

Introduction to Tanner Tool

BEGINNERS GUIDE

To begin a project the first step is to create a project

To do so click on File in the menu, and select new -> New Design and the following window

opens.

Click on the browse button and select the folder were the project has to be saved. Once this i

done, give a design name and click ok.

To create a cell, click on cell on the menu and select New View the following window opens




In the cell space give a cell name say inv or any name appropriate to the experiment an

click OK.

Once this is done the following window comes up.




On the left hand side window click on the add button and the following window comes up.




Now select the library by following the path given below.

My Documents / Tanner EDA /Tanner tool V13.0/ Libraries / All/ All tanner

And click OK

Click on the Devices option on the left hand side and the following window comes with a lis

of devices on the left hand side.




I. Perform DC Analysis, AC Analysis and Transient Analysis for the Inverter

circuit :

INVERTER DESIGN

To design an inverter a PMOS and an NMOS are required. Hence click on the left hand sid

device list for NMOS and the following window pops up.




As is visible on the left hand side an NMOS transistor is displayed. Click on Instance butto

and the following window comes up.

To change the name of the device the new name can be changed by giving a new name in th

instance name box. The device is selected and pasted on the cell window by click on th

right button of the mouse. To come out of this mode press ESC button.

The size of the device can be reduced or increased by scrolling the window.




Similarly select the pMOS device also and paste it in the cell window as shown in the sna

shot given below.




To connect the devices we need a wire which is available by clicking the button on the to

menu. Connect the gates and the drains of the PMOS and NMOS devices as shown below.




To select the sources click on the MISC option on the left hand side window. Now selec

GND and give it to the nMOS source as shown below and connect it using wire.


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Similarly select VDD and connect it to the source of the PMOS as shown below.




To do DC analysis select DC source from the path given below which is on the left hand sidof the window.

SPICE _ ELEMENTS -----Voltage source

The voltage source is renamed as Vdc and pasted on the cell screen and the +ve terminal i

connected to the gates and the ve terminal is connected to GND as shown below.




To give a voltage range of your choice take another instance of Voltage source and in th

properties window give the voltage range as 3.3 Volts as shown below.

Connect bulk of PMOS and NMOS transistors to the source of the devices using wire.

Also give the labels to the nodes by clicking L on the top menu and give appropriate lable

name such as where Vdd is given, give the label name as Vdd, where GND is connected giv

GND and input node name as in and output node name as out as shown below.




To print input and output voltages select Spice_Commands on the left hand side window

and then select the printvoltage option below and paste it on the cell nodes where ever it i

required. In the properties of Print Voltage select DC .In this case it is in the IN and OUT

node as shown below.




To conduct DC analysis click on Setup Simulation button which is a on the top menu next to

the simulation button. Then the following window pops up.




Select DC sweep analysis on the window and give the following parameters.

Source or parameter name should be the input source to be sweeped. In this case it is Vdc

Since h Spice code by default takes all voltage sources with a V prefixed, the source nam

will be VVdc.




start value = 0

Stop value = 3.3

Step = 0.1

Click on General.Here we have to give SPICE File Name, File Search Path and Librar

Files. SPICE File Name is the spice file which is created with the extension .tanner. Fil

Search Path is got by selecting the path below by browsing

My Documents/ Tanner EDA /Tanner EDA tools V13.0/Libraries/ Models

In the Library files path give the library file path as below.

My Documents/ Tanner EDA /Tanner EDA tools V13.0/Libraries/ Models/Generic _0.25li

TT

Do not forget to add TT after selecting the generic file.

Next select the spice file i.e. .sp file from the folder created by the user.

Now the window will look as given below.




Next click OK button.

Run the simulation.

Next T Spice will open automatically and will give the spice netlist as shown below




If there are no errors, W-EDIT which is the waveform editor will open automatically an

display the waveform expected as shown below.




Transient Analysis.

For doing the transient analysis, one has to use an pulse source. Hence in the S-Edit, removthe DC source and use the Pulse source by selecting the Spice elements in the left hand sid

menu and select the Voltage source in the options and in the interface select Pulse instead o

DC. The rise time, fall time, pulse width, period etc specifications can also be given as pe

the design specification.




Now paste the pulse source instead of the DC source in the S EDIT window as shown below

In the properties window of the Pulse source change the name and give vHigh as 3.3 V an

vLow as 0 V.

Select the print voltage and change the print analysis for both the node in their respectiv

properties and select TRAN option.




Select setup simulation option and select transient / fourier analysis option. In that enter th

following parameters.

Stop Time: 2u

Maximum Time step: 1u

Print Start Time: 1n

Print Time step: 10n

Use initial Conditions: False

Startup mode: Op

Again check for the library file, spice file etc in the general option as listed in the DC

analysis section. Once all the parameters are entered successfully , click OK and save the ce

design. Once this is done run the simulation by clicking on the simulation button.

Again T Spice opens automatically and runs the spice compilation and if there are no errors

W-EDIT opens automatically and the waveform is displayed as shown below.




It is clearly visible that the input and output waveforms are inverted.

AC Analysis.

The AC analysis is done by selecting AC input voltage source from the Spice_ Element

options.

In the properties window of the AC voltage source enter




Mag = 1m

Phase = 90

And Vdc which is the bias voltage and is calculated from dc analysis. This is approximatel

1.5V

A capacitor has to be put at the output node for AC analysis. A capacitor of 1nF or 1pF i

sufficient. The value of the capacitor is calculated depending on the design specification.

The schematic looks as below.




Once these parameters are setup, select the properties of Print voltage and select AC in th

analysis window.

Once all the settings are done, click on setup simulation icon.

Now select AC analysis and enter the following parameters

Start Frequency : 10

Stop Frequency: 100000K

Number of frequencies: 20

Sweep Type: dec

Analysis Name: AC

Again check for the library files and the spice file paths as in the case of previous analysi

case and click OK.

Once this is done click on Simulation button. T- Spice opens automatically and complies th

Hspice code generated automatically. If there are no errors, then the W Edit will open

automatically and the waveform will be displayed as shown below.




To calculate the cutoff frequency calculated Am / (2)0.5 and find out that value on the Y axis

Where this intersect with the ac analysis plot on the x-axis is the cut off frequency.




EXPERIMENTS UNDER TRANSIENT ANALYSIS

Experiment 1 : Design an Inverter for Symmetric delay.

i.e TLH = THL

Take Wn = Ln = 0.25 and change Wp. Start from Wp = 0.25u , 0.35u, 0.45u, 0.55u

0.65u, 0.75u

For these different values of Wp plot TLH & THL v/s Wp. Wp on X- axis and TLH & TH

on Y axis. The point where TLH & THL intersect is the Wp to be chosen for symmetri

delay.

Total delay Tp = (TLH + THL) / 2

For the above mentioned experiment take the following specification

C= 10pF

Fall time = 1ps

Rise time = 1ps

Period = 2us

Pulse width = 1us

In the simulation set up set the following parameters

Stop time = 10u

Max time step = 1u

Print start = 1n

Print time step = 1n

As Wp increases TLH should decrease and THL should increase.




Experiment 2: Design an Inverter for varying delay by changing the capacitances.

Total delay Tp = (TLH + THL) / 2

Keep all the parameters of the above experiment constant and vary load capacitances CL

3pF, 5pF, 7pF, 10 Pf, 12pF, 15pF

Plot a graph of CL on X axis and Tp on Y axis. As CL increases total delay Tp should als

increase.

EXPERIMENTS UNDER DC ANALYSIS

Design an inverter for a threshold voltage of given value by manipulating W and L values o

the pMoS and nMoS transistors.

EXPERIEMENTS UNDER AC ANALYSIS

Design an inverter for a given cut off frequency by manipulating load capacitance CL. Kee

the following parameters constant.

Wp = 0.55u, Lp = 0.25u, Wn =0.25u, Ln = 0.25u

Plot a graph of CL V/s Cutoff frequency.




II. Perform DC Analysis, AC Analysis and Transient Analysis for common

source amplifier :

COMMON SOURCE AMPLIFIER

EXPERIMENT UNDER DC ANALYSIS

Draw the following circuit in S- edit




Let W=0.5u and L= 0.25u .Use 10K ohm resistor and do DC sweep analysis as explained in

the previous section. Also print the input and output voltages. The following waveform

should be displayed.

The operating point is where the input and output plots intersect each other. Here it is 1.61V

Thus the result concluded is that the for a transistor with

(W /L ) = 2 the operating point is 1.61V.




EXPERIMENT UNDER TRANSIENT ANALYSIS

Draw the circuit for transient analysis as shown in the figure. Use an sinusoidal source.

Give offset the operating point calculated in the DC analysis.

Choose Transient analysis in the setup simulation window and give the following

parameters.




Stop time = 10u

Max time step = 1u

Print start = 1n


On running the simulation one will get the following waveform




EXPERIMENT UNDER AC ANLYSIS

To plot the ac analysis, draw the following circuit

Use AC source and give Magnitude as 1mV and Vdc =1.61V which is the operating poin

calculated in DC analysis. Use 10pF capacitor.

Select AC analysis in the setup simulation window and set the following parameters.







Sweep Type: dec

Analysis Name: AC

On running the simulation the following waveform is displayed.

To calculated the cutoff frequency calculated Am / (2)0.5 and find out that value on the Y

axis. Where this intersect with the ac analysis plot on the x-axis is the cut off frequency.

Change the load capacitance to get a particular cutoff frequency.




III. Perform DC Analysis, AC Analysis and Transient Analysis for common

drain amplifier :

COMMON DRAIN AMPLIFIER


To conduct the DC analysis of a Common Drain amplifier draw the following circuit. Selec

a DC source.




Let W=0.5u and L= 0.25u .Use 10K ohm resistor and do DC sweep analysis as explained in

the previous section. Also print the input and output voltages. The following waveform

should be displayed.

The output voltage follows the input voltage as shown above. The output voltage increase

after the threshold voltage is crossed which in this case is 0.3V.





Draw the circuit for AC analysis as shown in the figure. Use a sinusoidal source.

Give offset the operating point 0f 1.61V

Choose Transient analysis in the setup simulation window and give the following

parameters.

Stop time = 10u

Max time step = 1u




Print start = 1n



Calculate and see if the output voltage is a magnified signal of the input voltage and th

output voltage should be in phase with the input voltage.




EXPERIMENTS UNDER AC ANALYSIS

To conduct AC analysis draw the following circuit and use an AC source.

Use a 10pF capacitor. In setup simulation give the following parameters







Sweep Type: dec

Analysis Name: AC

On running the simulation the following waveform is displayed.

To calculate the cutoff frequency calculated Am / (2)0.5 and find out that value

on the Y axis. Where this intersect with the ac analysis plot on the x-axis is the cut off

frequency.

Here it is 5.54Mhz




IV. Perform DC Analysis, AC Analysis and Transient Analysis for Differential

Amplifier circuit :

DIFFERENTIAL AMPLIFIER


To conduct the DC analysis of a differential amplifier, draw the following circuit.

Let the current source be 100uA, and resistors of 10k each is chosen.

In the setup simulation window sweep voltagesource_1 source from 0 to 3.3V in steps o

0.1v and keep voltagesource_2 constant at 3.3V.




On proper compilation the following waveform is displayed.

The intersection point is approximately 3V. This is the operating point.

Similarly in the setup simulation window sweep voltagesource_2 source from 0 to 3.3V in

steps of 0.1v and keep voltagesource_1 constant at 3.3V.



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Draw the circuit for transient analysis as shown in the figure below.




Please note the following

In the voltage source properties select sinusoidal source. The amplitude of both the source

should be 100mV and one of the voltage sources should have negative amplitude otherwis

the difference signal will be zero.

In the setup window give the following settings.

Stop time = 10u

Max time step = 1u

Print start = 1n






It can be measured and seen that the output waveform is the amplification of the input signal





Draw the following circuit for AC analysis. Note that there should be a phase difference o

90 degree between the two sources and a capacitor is to be added at the output node.





Stop Frequency: 10Meg


Sweep Type: dec

Analysis Name: AC

On running the simulation the following waveform is displayed




To calculate the cutoff frequency calculate Am / (2) 0.5 and find out that value on the Y axis

Where this intersect with the ac analysis plot on the x-axis is the cut off frequency.

Here it is 15.93Meg Hz





V. Perform DC Analysis, AC Analysis and Transient Analysis for Single Stage

Operational Amplifier circuit :

SINGLESTAGEOPERATIONAL AMPLIFIER


To conduct the DC analysis of a single stage operational amplifier, draw the following

circuit.




In the setup simulation window sweep Vdc1 source from 0 to 3.3V in steps of 0.1v and kee

vdc2 constant at 3.3V.





The intersection point is approximately 3V. This is the operating point.

Similarly in the setup simulation window sweep Vdc2 source from 0 to 3.3V in steps of 0.1v

and keep Vdc1 constant at 3.3V.


Again the intersection point is approximately 3V which is the operating point.

If both the voltage sources are swept together, the following waveform is displayed




Where the output node is the node joining nmos_2 and the rd resistors 2.


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Stop time = 100u

Max time step = 1u

Print start = 1n






It is clearly visible that the output voltage is the amplified version of the input voltage.

Change W/L ratio for different amplification factors.







Sweep Type: dec

Analysis Name: AC





To calculate the cutoff frequency calculate Am / (2) 0.5 and find out that value on the Y axis

Where this intersect with the ac analysis plot on the x-axis is the cut off frequency

Here it is 239.37KHz





VI. Perform DC Analysis, AC Analysis and Transient Analysis for Two StageOperational Amplifier circuit :

TWO STAGEOPERATIONAL AMPLIFIER


To conduct the DC analysis of a single stage operational amplifier, draw the following

circuit.




In the setup simulation window sweep both vVoltageSource_3 source and vVoltageSource_

from 0 to 3.3V in steps of 0.1V.



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EXPERIMENTS UNDER TRANSIENTANALYSIS

To conduct the transient analysis of a single stage operational amplifier, draw the followin

circuit.









Stop time = 100u

Max time step = 1u

Print start = 1n



The yellow waveform is the final output which is having a peak to peak amplitude of

690.2mV as shown below.




Where as the green coloured waveform is the input signal which wjen magnified one can

measured the peak to peak voltage of 20.99mV as shown below.




It is clearly visible that the output voltage is the amplified version of the input voltage.

Change W/L ratio for different amplification factors.







Sweep Type: dec

Analysis Name: AC



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To calculate the cutoff frequency calculated Am / (2)0.5 and find out that value on the Y axis

Where this intersect with the ac analysis plot on the x-axis is the cut off frequency