the zen of analog design - preview
DESCRIPTION
Preview of our "Zen of Analog Design" seminar www.sahyogee.com/zenTRANSCRIPT
The Zen of Analog The Zen of Analog The Zen of Analog The Zen of Analog Design Design Design Design –––– A A A A PreviewPreviewPreviewPreview
March 27, 2013
Because Education should change life...
� Give everyone a small slice of Analog to take back to your work or study.
� Present a glimpse of the beauty of Analog
� To impress upon everyone the importance of Analog concepts in all domain of electronics & communication.
Aims of this seminar
The quest of Analog design …
VOUT VIN
The output follows the input exactlyexactlyexactlyexactly.
“Response” matches “stimulus”.
...An ideal buffer!...An ideal buffer!...An ideal buffer!...An ideal buffer!
Ideal buffer: VOUT=VIN
Another attribute of ideal buffer
VOUT VIN
Should support any ILOAD.
ILOAD
Ideal buffer: VOUT=VIN for any ILOAD.
Analogy with THE most critical facet of human life …
Response Stimulus
Our Relationships!
Husband-Wife
Parent-Child
As we will look to realize the ideal buffer, we will get some insights!
Friendships
Eg. Couple has planned a long overdue vacation �
Is there a *right* response to this stimulus?
What factors will determine how they respond?
VIN VOUT
� Husband’s main customer throws an urgent request,
Will their *limits* get tested?
VOUT VIN Response Stimulus
Husband-Wife
Healthy relationship � able to respond to a stimulus in the most apt manner
We will elaborate …
Ideal buffer / Healthy relationship
Ideal buffer � VOUT follows VIN accurately
What is *LOADING* in the human analogy?
Response Stimulus
Loading Painful boss
Demanding kids
Healthy relationship � healthy response to stimulus in presence of “loading”!
In-laws!
Painful prof
A story will help!A story will help!A story will help!A story will help!
we travel back in time …
3300 years!
The palace of Pharaoh Tutankhamun!
To meet the protagonists of our story,
Very Large Scale Mummification
Aman-Ra has a manager: Gamen-Ra
Gamen-Ra is always suspicious of Aman-Ra Every week they have a project review meeting
Are you sure you are holding up the datasheet the right
way?
We will visit their story soon...
But first we will look to pick up the language of Analog design!
Let’s start with ABC …
… The Voltage source
What is an ideal voltage source?
One that tries to impose a constant voltage at its output …
… irrespective of the current drawn from it
+ - Circuit Vs
Io
What is the I-V curve of an ideal voltage source?
V
I
Vs
Constant voltage for any current
But we will be using a different element for modeling relationships.
What is an ideal current source?
One that forces its current on to a circuit …
… but is capable of taking any voltage across itself
Circuit Is Vo
+
-
The current source!
Is
What is the I-V curve of an ideal current source?
V
Is1
I
Forces constant current Capable of taking any voltage
Is1 Is2
Is2
Note: Two current sources in series would not find a “meeting point”
How would a *non- ideal* current source look?
V
Is1
I
It is possible for two non-ideal current sources in series to establish a meeting point
X
Is1 Is2 Is2
Now let us create a human analogy...
CURRENT = OUR THINKING/ VIEWSCURRENT = OUR THINKING/ VIEWSCURRENT = OUR THINKING/ VIEWSCURRENT = OUR THINKING/ VIEWS
VOLTAGE = OUR RESPONSE TO A STIMULUSVOLTAGE = OUR RESPONSE TO A STIMULUSVOLTAGE = OUR RESPONSE TO A STIMULUSVOLTAGE = OUR RESPONSE TO A STIMULUS
Me
You
My views
Your views
Our combined response to a stimulus
The fascinating thing about humans is that we are capable of almost any response to a stimulus...
As long as we get to impose our views!As long as we get to impose our views!As long as we get to impose our views!As long as we get to impose our views!
The need to always “be right” makes us like a current source!The need to always “be right” makes us like a current source!The need to always “be right” makes us like a current source!The need to always “be right” makes us like a current source!
We revisit Aman-Ra and Woman-Ra
They meet each other and fall in love...
XXXX
A perfect *Operating point* gets established!
What is a“perfect operating point”?
Even a “perfect” relationship has limits on the range of stimulus!
VOUT VIN
VDDVDDVDDVDD
GNDGNDGNDGND
In our buffer analogy, this was…
We can visualize these bounds as:
V VDD GND
Ideal “operating point”
The margin for VOUT when VIN reduces
The margin for VOUT when VIN increases
“Headroom” in Analog parlance
Similar concept for a relationship!