The Catches: My first encounter with Current Feedback Op-Amp

So to say, I was evaluating a circuit given in manufacturer’s reference circuit, being young and naïve (ignorant too), I just get the parts and put it in together – most of the time the circuit works – but when debugging one particular non-working circuit – something was not working accordingly.
So it was the time that I look at the datasheet of that amp – and found out that it was current feedback op-amp – not the assumed typical voltage amp – it turns out to be that current feedback op-amp are generally faster – and the behaviour differs as well.
for more details refer to wiki:
http://en.wikipedia.org/wiki/Current-feedback_operational_amplifier
Lesson Learnt:
Textbook op-amp circuit is generally voltage feedback op-amp – and there are much more in the market then what offered in text book.

Purpose/Introduction of this blog

To provide an introduction of analogue /mixed circuit design consideration in

1.       As little equation

2.       As much diagram as possible – A picture is worth a thousand words.

3.       As gradual/intuitive as possible

4.       Talk about each aspect in 1-2 page max

The bad news is that there is too much information on this subject for any decent mind to pick it ALL up. It takes time to know enough to be good in this.

But the good news is that, you don’t need to master all at once, starting with a desire to learn, you can consider the below to get started

1.       Read through basic stuffs (Kirchhoff’s Law, Thevenin's theorem …) – remind yourself on what’s the purposes of the stuffs you learn, and no memorization please

2.       Seek and read articles that talk about the real life circuit – things that people learnt it the ‘Hard Way’ - the book “The Arts of Electronics” is one of my favourite.

3.       Live by the motto “seek to understand, then to be understood” – when things don’t work, take it easy, isolate the problem, seek to understand the problem, the solution will come automatically once you know what’s going on.

4.       Always hands on – reading won’t get you far, try the following

a.       Know what needs to be build

b.      Takes a couple of days to do background study – you don’t have to fully know all the details though

c.       Build it – possibly through simulation software, then prototype it with most basic stuffs

d.      Test it up – with the understanding that things will not work as expected (for average person, getting the expectation right is utmost important, coz when things don’t work (and trust me, usually it won’t)). This will allow you to avoid the frustration

e.      Debug the circuit – understand the root cause, cross check with theory when things don’t work as expected.