Analog and RFIC Design InterView Question

• General_interview_questions_answers
  
• Preapring for your interview
  
• Analog_rfic_interview_preparation
  
• Question paper for analog design interview
  
• Another Question paper in analog integrated circuit design
  
• One old Question paper for Texas instruments, India, (collected)
  
• VLSI_design_interview_questions1
  
• Commonly asked interview questions
  
• Common entry level questions
  
• Common interview questions good to look at it
  
• VLSI_design_interview_questions2
  
• VLSI_design_interview_questions3
  
• General Electronics and communication interview question
  
• RF design interview question
  
• Typical RFIC design flow, The design flow will vary from company to company
  
• Typical WLAN block diagram
  
• basic analog design reports
  
• Job Hunting Guide for Analog/Mixed signal Circuit Design - by Fuding Ge
  
• Question1: What is Slew Rate and how is it used to design an op amp?
  
  Answer: Slew Rate (SR) is the rate at which the output voltage changes for a large scale change in voltage at the input. Thus SR is in units of volts/time. The design project specifies SR is 400nsec for a 1 volt step. This means that SR = 1V/400nsec = 2.5V/usec. Note: the slew rate is not a time, but a rate (1/time).
  You will use the specification given for slew rate to determine the bias current of the differential stage, since this is the limiting charging time* (see note below). Thus you can calculate, Ibias > (SR)(Cc) and set Ibias so that it is greater than the product of the slew rate times the compensation capacitance. This equation is derived from the basic relations of
  Q = C V = I t, where Q is charge and t is time.
  When you calculate this value it will be rather small, and I suggest you use a current value slightly larger, maybe even 5-10 times larger, to insure you meet the SR specification.
  * (note from above) The slew rate is limited either by the output of the differential amplifier or the output of the second stage, whichever is the slowest at charging the output capacitance. You can determine this from
  
  t = (C)(V)/(I)
  If we assume that we are interested in changing the charge to give a 1 volt change in output (as in your design project), then we can calculate each of these to charging times from
  t = Cc/Ibias, for the differential stage
  
  t = Cl/I6, where Cl is the load capacitor, I6 is the current in the second stage, for the second stage
  (Note that both of these equations assume that the node capacitance will be dominated by Cc and Cl, which is generally a good assumption).
  Since Ibias is normally much smaller than I6, the slew rate is typically limited by the differential stage and thus we write, SR = Ibias/Cc. However, you should probably check to see which of these time constants is the largest, and if you find that the second stage stage is longer, then you should adjust the currents so that SR = I6/Cl.
  
  

Websites about PLL Design

MIT High Speed Circuit and System Group
EE 536, Winter 2006 - University of Washington

Free Alternatives to Matlab

Matlab・has become the de facto standard for DSP system design and simulation. However, Matlab has two problems: 1) it's expensive, and 2) it costs a lot. Fortunately, there are alternatives: Free Clones. Whatever else you can say about them, these Free Clones offer two significant advantages: 1) you don't have to pay for them, and 2) they're free.

The major Matlab clones are Scilab, Octave, and Rlab. None are true "clones", because none offer 100% compatibility with Matlab's "m-files". However, they all provide number-crunching power similar to Matlab, at a much better cost/performance ratio (since they're free!)

Essentially, Scilab, Octave, and Rlab are interpreted, matrix-based programming languages. They share with Matlab:

The use of matrices as a fundamental data type. Built-in support for complex numbers. Powerful built-in math functions and extensive function libraries. Extensibility in the form of user-defined functions.

Scilab
In some ways, Scilab may be the "best" of the Matlab clones. Scilab has many strengths, including excellent documentation (the signal processing manual is an education in itself!) and excellent support (via e-mail and its own newsgroup). Best of all, for Windows users, Scilab is supplied not only as source code, but as a Windows binary. Scilab is mostly--but not completely--compatible with Matlab. (Scilab now comes with a Matlab-to-Scilab translator, but that's still a bit immature.) For more information:

• Scilab Home Page


• Scilab Documentation and Support Page


• Scilab Online Documentation


• Scilab
  Signal Processing Toolbox Functions


• Scilab Download Page

Octave
Like Scilab, Octave is another mature, high-quality Matlab clone. If you use a Unix-like operating system, Octave may be a better choice than Scilab because it reportedly offers better compatibility with Matlab. (However, for Windows users, Octave suffers the comparitive disadvantage that the binary distribution of it is quite complicated to install.) For more information:

• Octave Home
  Page


• Octave
  Documentation Page


• Octave
  Download Page

Rlab
Rlab is the least Matlab-compatible of the three. Rlab does not try to be a Matlab clone but instead, in the words of its creator "borrows what I believe are the best features of the Matlab language and provides improved language syntax and semantics." For more information:

• Rlab Home Page


• Rlab
  Reference Manual


• Rlabplus

Others
JMathLib - A Java Clone of Octave, SciLab and Matlab
TeLa
Algae
Yorick
Euler
Python with NumPy and SciPy
The R Project for Statistical Computing (not a clone, but same matrix multiplication plus more)