Reddit mentions of IC Op-Amp Cookbook (3rd Edition)

• I work in the semiconductor industry doing applications engineering for precision op-amps and voltage references. At its most basic level, the goal of apps engineering is to work with customers to design parts into their systems and solve technical issues that come up. The reality is that we're used for anything our superiors deem worthy of our time, but that's a story for another reddit thread.
  
• Not much specialized software -- maybe OrCad for a SPICE simulation from time to time. Standard office apps for editing datasheets and app notes. Lots of email. MS Outlook is quite possibly the worst email client ever created. Skype for talking with colleagues overseas. Firefox for cruising reddit.
  
• I work for Analog Devices in San Jose.
  
• Answers to your questions:
  
  Let's start with the basics. When you first start working with op-amps, they give you a couple of golden rules: 1.) Gain-bandwidth product is infinite, and 2.) when there's a feedback loop, the voltage at the inverting and non-inverting terminal are equal. What they don't often tell you is that there is no such thing in real life.
  
  Non-ideal traits for an op-amp include things like offset voltage, bias current, offset temperature drift, and limited gain-bandwidth product. You can think of offset voltage as an extra little DC voltage source sitting on the non-inverting input, and bias current as a little current source sitting between the two input terminals. Maybe these are the non-idealities you had in mind. These shouldn't throw you off too badly, though -- if you can solve an op-amp circuit normally, the easiest thing to do is use superposition to solve for each input separately, then combine them to get the response for the whole thing. I'm sure you can google for how to do this.
  
  Nearly all op-amps are designed to have a huge open-loop gain over a small frequency band, but they are way unstable and hardly usable as such. That's why we use feedback loops. What a feedback loop essentially does is sacrifice the high open-loop gain for a lower, more stable closed-loop gain over a larger frequency band. That's where the gain-bandwidth product comes into play -- if you have an op-amp with 80 dB of open-loop gain over 100 kHz and a cutoff slope of -20 dB/decade, you can sacrifice 40 dB of gain and use it to amplify signals over 10 MHz instead.
  
  My best advice is to ditch the book and use google to your advantage. I found this note that will probably help you with what you're trying to do.
  
  Also, try searching for app notes on op-amps on semiconductor manufacturers' websites. National Semiconductor, TI, Linear Technology (and yes, even Analog Devices), have tons of app notes that can explain nonlinearities. Another good resource is this book.
  
  Enjoy.

The IC Op-Amp Cookbook by Walter Jung has hooked thousands of engineers and hobbyists. Strongly recommended.

1. Read those two books and understand them. Now you can calculate the closed-loop gain of any opamp circuit.
   
   
2. Find an Opamp Circuit Collection, either in manufacturer's Application Notes or in books. ONE , TWO , THREE , FOUR , FIVE , SIX . Do a table lookup: find your circuit in their collection. Then read their analysis, including their calculation of its gain. Then decide whether you trust them.
   
   
3. Find an EE who has taken and passed a couple of courses on circuit design with opamps. Pay her to analyze your circuit and explain it to you.