IC fabrication and packaging
What does it mean if an integrated circuit comes in DIP form? What does the acronym "DIP" mean?
Challenge question: what is the standard spacing between pins on a DIP IC?
Explain to your students that DIP packaging is not used for integrated circuits with more than 48 or so pins, and then ask them why that might be.
Where are the power supply pins most commonly located for integrated circuits in the standard "DIP" form? Some manufacturers of high-speed digital ICs are now relocating power supply pins to the middle of the package, like this:
Explain the rationale for this non-traditional pin assignment.
Centered power supply pins on modern high-speed DIPs exhibit less parasitic inductance than corner-located pins.
Follow-up question: what is the best way to determine pin assignments on any given integrated circuit?
Let your students know that even some of the older integrated circuits had "weird" power supply pin locations, so they cannot assume corner-pins for every older DIP they see! An example of this is the 2102L static RAM, or the 4049 CMOS hex inverting buffer.
Even stranger is DIP chips with multiple +V and GND pins. Good examples of this include the 74AC11004 and the 74AUC16373.
Find one or two real integrated circuits and bring them with you to class discussion. Identify as much information as you can about your ICs prior to discussion:
- Part number
- Date of manufacture
The purpose of this question is to get students to kinesthetically interact with the subject matter. It may seem silly to have students engage in a ßhow and tell" exercise, but I have found that activities such as this greatly help some students. For those learners who are kinesthetic in nature, it is a great help to actually touch real components while they're learning about their function. Of course, this question also provides an excellent opportunity for them to practice interpreting component markings, use a multimeter, access datasheets, etc.