I would like to simulate & lay out a circuit by hand (10 xtor maybe?)

Martin C.

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Mar 25, 2012, 2:35:00 AM3/25/12

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I am not an IC designer but I would like to, for fun, simulate and lay
out a circuit by hand that I can actually understand.

To get a head start, where do you suggest I find a small (ten, maybe
twenty transistors) sized circuit that I can actually understand (being a
business major)?

I found plenty of unsized circuits - which are, in reality, topologies
with missing parts - but - I was hoping to start with a working cmos IC
circuit that works out of the box so that when I simulate it, I could
learn what it is doing - and - so that I could begin to lay it out based
on the actual lengths and widths in the simulated schematic.

Is there a web-available source for very simple sized analog schematics
for learning purposes (i.e., something more than just a digital inverter
block, e.g., an analog op amp, band gap, comparator, vco, pll, etc.)?

Robert Macy

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Mar 25, 2012, 9:03:48 AM3/25/12

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On Mar 24, 11:35 pm, "Martin C." <martincella...@nospam-gmail.com>
wrote:

If he missed this and doesn't jump in, look up Jim Thompson. Probably
the BEST IC deisgn source and he's tutorial in nature.

Martin C.

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Mar 25, 2012, 10:53:14 AM3/25/12

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On Sun, 25 Mar 2012 06:03:48 -0700, Robert Macy wrote:

>> Is there a web-available source for very simple sized analog schematics
>> for learning purposes (i.e., something more than just a digital
>> inverter block, e.g., an analog op amp, band gap, comparator, vco, pll,
>> etc.)?
>
> If he missed this and doesn't jump in, look up Jim Thompson. Probably
> the BEST IC deisgn source and he's tutorial in nature.

Thanks for the tip.

I found this web site looking up "Jim Thompson IC Design":
http://www.electronicspoint.com/datasheets-schematics-manuals-and-parts-
f87.html

But it seems to be mostly about discrete components.

I also bought the "R. Jacob Baker" book titled:
CMOS Circuit Design, Layout, and Simulation

The problem (so far) is that there isn't a single sized CMOS schematic in
the entire book. Of course, if I were a 'real' EE, the book would be
enough for me to do the sizing myself ... and, I'm sure, that's the right
approach if I were trying to be a circuit designer.

But, for my needs (bearing in mind I'll never be a circuit designer), I
just want a simple analog 'sized' cmos schematic (any design that is
analog and not digital in nature) that I can simulate and probe (and that
a kid could understand once I fully understand it).

I 'do' have an 80-transistor sized op amp circuit, for example - which
works - but for two reasons it's too much for me.
1. It is way too much to lay out for my hand-editing purposes
2. It is way too complicated for me to understand what's happening at
every node

I realize this is an unusual request (as most people simply size their
own schematics based on topologies) - but I'm just looking for the
perfect circuit to learn and understand for myself (and then teach my
young son).

There must be a simple sized cmos analog schematic out there ... I just
need to find it.

rickman

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Mar 25, 2012, 6:14:28 PM3/25/12

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On Mar 25, 2:35 am, "Martin C." <martincella...@nospam-gmail.com>
wrote:

You might be interested in trying the Cypress PSOC devices. They also
include a microprocessor but have analog building blocks on chip. The
tools are free and I believe they have some level of simulation. Or
if you get really hooked you can buy an eval board and try building
your circuit and testing it.

Rick

Martin C.

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Mar 25, 2012, 9:31:49 PM3/25/12

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On Sun, 25 Mar 2012 15:14:28 -0700, rickman wrote:

> You might be interested in trying the Cypress PSOC devices.

I did find 'some' simple analog circuits at the various edu sites but not
yet a simple sized schematic of general analog use ...

Here's what I have ... so far ...

This layout reference doesn't have sized schematics:
http://ims.unipv.it/Microelettronica/Layout02.pdf

This paper has a CMOS bandgap reference, where maybe I can figure out
sizes:
www.aicdesign.org/SCNOTES/2010notes/Lect2UP010_(100324).pdf

Or this one has a voltage reference that I might be able to simulate:
http://www.ee.nchu.edu.tw/Pic/Writings/677_01705059.pdf

This seems to have a sized schematic of reasonable simplicity:
http://weble.upc.es/rfcs/Material/Labs/RFCS_LAB1.pdf

This paper seems to have transistor sizes for a Miller amplifier:
http://www.see.ed.ac.uk/~s0571365/Files/Articles/Analog/Design/_Analysis%
20and%20design%20of%20amplifiers%20and%20comparators%20in%20CMOS%200.35um%
20technology_Cortes03.pdf

This seems to have opamp sizes:
http://kazus.ru/nuke/modules/Downloads/pub/196/0/OpAmp-Final_cadence.pdf

Martin C.

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Mar 29, 2012, 3:16:48 PM3/29/12

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Does this ten-transistor CMOS MOSIS opamp test design look like a
reasonable first design (with sizes) to capture, simulate, layout, &
extract parasitics, and then re-simulate?

http://picturepush.com/public/7908714

That design is taken from this document:

http://www.asee.org/documents/sections/middle-atlantic/spring-2008/02-
Design-Simulation-and-Testing-of-MOSIS-Fabricated-CMOS-Operational-
Amplifiers-for-Class-Projects-in-an-Analog-IC-Design-Course.pdf

Martin C.

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Mar 30, 2012, 1:09:13 AM3/30/12

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Here's another op amp with transistor sizes ...
http://jennisjose.webs.com/operationalamplifiers.htm

Martin C.

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Apr 1, 2012, 1:14:17 AM4/1/12

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This two-stage op amp with an n-channel input pair circuit looks very
nice as a beginner simulation & layout project:
http://s.eeweb.com/members/neil_tsai/projects/2011/03/22/
CMOS_OpAmp-1300771784.pdf

They designed a two-stage CMOS operational amplifier with low power
dissipation and high gain in the AMI C5N 0.6μm process technology.