– a monolithic inductor optimization tool by Niklas Troedsson

1. –a monolithic inductor optimization toolbyNiklas Troedsson Indentro

2. Pep Talk Indentro has a website, why this presentation then ? To fire-up and get going real fast , Cook-book approach A formal introduction about the tool is given by Niklas @ Indentro It is important to look at the weblink In simple terms, it is a tool that can give the Dimensions, Parasitics, Self- resonance frequency, Q-factor, Layout, etc. of an Inductor for a required value of Inductance So, what is the big deal? We have formulas for everything, Right? Yes we do !!!Page 136, Thomas H. Lee, The Design of CMOS Radio-Frequency Integrated Circuits (Course text) To appreciate Indentro, try your hand @ Problem 3 Ambitious? Indentro has an option for more accuracy by making use of Maxwell's equations – 'Fasthenry' is the name of the tool In what follows, there will be slides and explanations about various features of the tool right from the start ***All Red words are clickable

3. Installation Guide • All this has to be done in Windows pc, if you have to design inductors for the laboratory, you have to do all this before the lab-session1) Download the .zip file@ Download, unzip it2) The contents after unzipping will be in this folder, 3)Inside, there will be, , paste it on the “Desktop”4)Fasthenry@Fasthenryfetches a '.exe file.' Double click (install) it. 5) Copy the file, C:\Program Files\FastFieldSolvers\FastHenry2.exe6)Paste it in , which is inside the folder in (3)7) Find in folder in (3), double click, that will fire-up Indentro

4. 1) After it fires-up, feed in the values EXACTLY as in the screen sheet on the right. Everything else stays default. Radius Width Spacing No. of turns No. of Corners 2) Then, click here 3) Now, feed in different values and interpret the results with pictures on Page 137 of course - text. Just play until you know what is happening!!! 4) Double click here and wait for 2-3 seconds

5. Depending on the technology (for example 0.35 um or 0.13 um) used, the details about metals, poly, etc. is given in test_tech.m located at, (refer Slide 3). The user of the tool has to make appropriate changes in the file according to the technology in use For the laboratory in the course, download the file @ TechFile. Rename the file as, 'test_tech.m' Place the file in The technology file that comes with Indentro is @Technology. You don't have to do anything with this file, just have a look to see how it looks

6. 1) After following the steps on Slide 4, feed-in the values as shown in the screen shot on the right and click here 2) Observe the Layout and interpret the meaning of Top Metal, Cross Metal Example: The picture on the left is the layout of a Single -turn, Symmetrical inductor with a patterned shield. This example has nothing to do with the working of Indentro. The only reason why it is here is to show you a shield if you have not seen one before In short, a patterned Shield improves Q. It is generally made of Metal 1. The pink metal strip is the inductor, backgound stripes make the shield Next Slide

7. 3) Click here 4) Change the values in the form as in the screen shot on the right and click “OK” button here

8. 6) Step 5) gives and Click “OK” 7) Click “Results” button Pops up!!

9. 8) You will notice from the popped up “Results” form (previous slide bottom- right) that there are 10 rows that have give the same inductance value ( ) of 0.1 nH. Let's say you are interested in high Q case .i.e., First row. Now, in the “Main – Indentro 2005 form, click “Collect” here 9) Notice the change in “Ro” value in the form from 200 to 70. Now click here A “Results” form will pop-up. Keep that form open click here. A model of the inductor with all the parasitics involved will pop up. Continue to next slide if you are interested in FastHenry, otherwise, you are home. Bye-bye!

10. Most Important Slide – No Jokes Sometimes, buttons on the “Main – Indentro 2005” form might not respond to the mouse. Do Not Panic!!!! No restarts necessary. Don't blame Microsoft. Do an 'alt + tab' and if you see, click “OK”

11. For Nerds Now, let's say you are ambitious, real-practical, unfriendly,..., wise nerd. You will say “All this is nice but what about the electromagnetic effects that can cause changes which are hard-to-calculate using formulas ? - Take it easy boy ! For people like you, Niklas has incorporated FastHenry into his tool. 1) All the steps until the previous slide have to done. Then, click here 2) Click “OK” in the form that pops up. The only changes to make are “fmin” and “fmax” if needed. To know what the other parameters mean, refer, C:\Program Files\FastFieldSolvers\FastHenry2\FastHenry_User_Guide.pdf 3) Click here In the form that pops up, click Next Slide By any chance if no buttons on the “Main – Indentro 2005 work, remember what was said in the previous Slide!!! “alt+tab” trick

12. 4) Screenshot on the right pops up. Click and select “indentro_fasthenry.inp” Leave all the other values to default 5) Click 6) A form will pop up, Wait until you see “Total: “ in the bottom of the form The time taken is proportional to the complexity of the chosen inductor dimnesions 7) Close the form and “OK” the Attention window. If after closing the form, nothing pops up, do the “alt + tab” trick Next Slide

13. 8) Back to the “Main – Indentro 2005” form, click 9) “Results” form will pop up. Click these two buttons to see layout and schematic 10) Compare the difference between the results from Indentro (Row 1 bottom right screenshot on Slide 8) and Fasthenry

14. THAT'S IT! If you want to give any feedback about the presentation, mail, Vara: es06vpg@es.lth.se