Introduction
The Art of Electronics (AoE) book is full of tips and tricks that make the process of designing a circuit quicker and more intuitive. The entire left column of page 6 is
Most of these questions are quick and review. The last two require using your reference materials (Razavi and slides) to get the information you need.
1. Questions
1.3. AoE Exercise 1.4
Page 6.
Equation (1.5) works for any number of resistors in parallel. The “parallel resistor equation” you remember is just this formula with two resistors and simplified to a single fraction — do that 40 seconds of algebra to show this to yourself.
Do this “show” (proof) exercise by first drawing a schematic of 3 or more resistors in parallel. Then do circuit analysis to find the equivalent resistance of the network without using a parallel resistor formula, e.g. using equations generated from Ohm’s law, KCL, and KVL.
1.4. AoE Exercise 1.5
Page 6.
- Power rating of a resistor
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The maximum power that the resistor can absorb (and therefore increase in temperature) under “rated” conditions.
This is usually at the maximum ambient temperature specified for the resistor, but may have other and more conditions. For example, a 1/4 W resistor can absorb much more power if it is submerged in ice water.
1.5. AoE 1.5 followup
The resistors in your “Analog Parts Kit” that you received in the package with your Analog Discovery 2 have 1/8 W ratings.
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If your power supply outputs up to 10 V maximum, what is the smallest value of resistor that is guaranteed to never exceed its 1/8 W power rating in any connection arrangement across this supply?
Another way to think of this problem is: below what resistor value do you need to concern yourself with the resistor possibly getting too hot?
1.6. ni vs temp for silicon
Find the values of the intrinsic carrier concentration, ni, for silicon at the temperatures in the table. Also, at each temperature, what fraction of the atoms are ionized? (A silicon crystal has about 5x1022 atoms/cm3).
Temp \((^\circ C)\) | ni (#/cm3) | #ionized / #atoms |
---|---|---|
125 |
||
75 |
||
20 |
||
0 |
||
-55 |
2. Submission
Submit your 7 problem solutions as a single PDF file with all your work.
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It is preferable for each problem to begin at the top of a new page. Use your judgement for when it is reasonable to have multiple problems on a page.
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Doing this on engineering paper is even better. The College sells the best stuff at-cost, see Tina in the CoE office.