I was recently interviewed by EEWeb for the Featured Engineer edition. EEWeb, an electrical engineering publication, has many remarkable sections, including Analog Design, RF Design, tools, jobs, projects, and even a comic section. Of interest is the EEWeb forum, which is a growing discussion board organized in categories.
Here is an excerpt from the interview:
EEWeb: Do you have any tricks up your sleeve?
Adrian S. Nastase: I have a few rules when it comes to designing circuits:
Mother Nature always wants to challenge you. So, calculate everything and expect the unexpected.
Kirchhoff’s Laws are always true. This means that, if the sum of voltage drops on a loop does not equal zero, there is another component in that loop that has a voltage drop and you are not aware of it. By the same token, if the sum of currents in a node is not zero, it means that there is another signal path coming out of that node which is hidden from you.
Signals are always differential. Never treat your ground as an absolute zero volt trace, because it never is.
Zero does not exist in analog or mixed signal design. There is no such thing as zero voltage, zero current, zero ohms, zero inductance or zero capacitance. Depending on your design specs, one of these so called “zeros” will quickly show you that it has a non-zero value. As such, I always think in dB. For example, I know I will never have zero noise in a system, but if my noise to signal ratio is -100 dB, great. If it is -120 dB, awesome. If it is -140 dB, super. Knowing that you cannot achieve that zero, makes you think twice when planning your PCB layout …
For other electrical engineering tips and much more, read the interview at http://www.eeweb.com/spotlight/interview-with-dr.-adrian-s.-nastase