As an analog applications engineer, much of my problem-solving involves recommending application circuits for customers to use as subcircuits in their overall product design. Thus, I understand the need for standard values, formulas, printed circuit board (PCB) characteristics and shortcuts for predicting performance.
A colleague of mine, Tim Green, has about 32 years of experience, of which 16 are in board-/system-level design. When I asked him how he handled these common design aids, he opened his file cabinet and pulled out a folder stuffed full of dog-eared and well-worn papers he’d collected over the years of his favorite design collateral. One of the things that fell out was a small 25-page booklet called “The Burr-Brown Electronic Engineers Pocket Reference,” published in 1994.
That booklet was the motivation for Tim and I to modernize, simplify, organize and electronically publicize the new Texas Instruments Analog Engineer’s Pocket Reference (Figure 1).
Figure 1: TI’s new Analog Engineer’s Pocket Reference inspired by a 1994 Burr-Brown booklet
One general problem with pocket references is that you have to be really familiar with them. In other words, when confronted with a difficult problem, you might resort to a Web search before using the pocket reference if you don’t know that the answer is in the pocket reference.
So in order to help familiarize you with the new TI pocket reference, I have put together some questions. Try to answer the questions using the pocket reference and you will gain a much deeper understanding of the book’s powerful content.
Question 1 (hint: Analog section):
Referring to the circuit below, what is the phase shift at 100kHz?
Question 2 (hint: Amplifier section):
Referring to the circuit below, what is the rise time for the 20mVpp step wave input? Note that this is a small signal step and the OPA209 has a gain bandwidth product (GBW) of 18MHz (data sheet SBOS426).
Question 3 (hint: Amplifier section):
What is the noise spectral density of a 10kΩ resistor?
Question 4 (hint: Amplifier section):
Given the transient closed-loop waveform shown below, what is the loop gain phase margin?
Question 5 (hint: PCB and Wire section):
Referring to the figure below, what type of package is this?
Question 6 (hint: Sensor section):
What is the resistance for a PT100 resistance temperature detectors (RTD) at 100℃? Assume that the RTD adheres to the ITS-90 standard.
Question 7 (hint: A/D Converter section):
Calculate the effective number of bits (ENOB) for an analog-to-digital (A/D) converter assuming signal-to-noise and distortion (SINAD) (dB) of 75dB.
For the benefit of those who are still working through the problems, please do not post answers in the comments. I will post the answers next week. Good luck!
Download the Analog Engineer’s Pocket Reference to get often-used A/D conversion formulas in one place.