PHYS345 Electricity and Electronics

Working with Integrated Circuits



Develop working knowledge of D-type flip-flops and state counters.
Gain familiarity with integrated circuit data sheets.
Gain experience working with real integrated circuits and logic test equipment.

Equipment List
Global PB-503 analog/digital Proto-Board.
Integrated circuits for digital logic, NAND gates and D flip-flops.
Digital logic probe.
Wire of various colors and wire strippers.

Examine the Proto-Board powered breadboard. The Proto-Board has three basic units, each with 8 groups of 25 terminals and 128 groups of 5 terminals. The terminals in each group are connected together underneath the board. A sample piece showing the internal connections is available for inspection. Wires, resistance leads, capacitor leads, and IC leads plug directly into the terminals. The pin pattern on standard integrated circuits permits the IC to be plugged in straddling the centerline of each unit. Four terminals in each group connected to an IC pin remain free for further connections. You may use your multimeter in resistivity or continuity mode to confirm the wiring pattern on your breadboard.

The Proto-Board has three built-in power supplies. Most digital IC circuitry operates with a +5 V supply, which is provided on the boards. Analog IC circuitry usually operates with matched positive and negative supplies, typically +/-15 V. The Proto-Board has power supplies which can be varied from +/-5 V to +/-15V. It also has a large number of switches, controls, indicators, as well as a built-in function generator.

All circuits will be set up on the Proto-Board. At the top of the board there are bus strips which should be connected to ground and to the outputs of the +5 V. When possible, use red wires for positive power and black wires for ground connections to facilitate debugging by the laboratory instructor or others. Switch the Proto-Board off when making connections.

Proto-Board for wiring IC circuits

Top and bottom view of Proto-Board

Wiring Suggestions
Avoid placing wires over the ICs. You may need to switch ICs after the wiring is completed; this is often needed if one the ICs is suspected of not working properly.

Do not use wire of a particular color indiscriminately. For example, use a color scheme for the various outputs of the flip-flops so that you may keep track of the Q's.

Examples of good and bad Proto-Board wiring

Prime Number Counter
Wire the prime number counter following the wiring diagram created in the previous lab exercise. When it is working properly, demonstrate it to your laboratory instructor.

Prime number counter
One possible realization of the prime number counter

Data Sheets
Integrated circuit packages available in the lab for this exercise include:

Relevant Online Resources
74HCT Digital ICs, listing from RadioShack
Includes some Motorola, National Semiconductor, and Texas Instruments data sheets.
    74HCT00, Quad 2-Input NAND Gate
    74HCT00, Quad 2-Input NOR Gate
    74HCT74, Dual D-Type Flip-Flop
    74HCT175, Quad D-Type Flip-Flop
Logic Data Sheets from Harris Semiconductor
Logic ICs from Motorola
Logic Products from Texas Instruments
Digikey, retailer of electronics parts

Last updated November 18, 1998.
Copyright George Watson, Univ. of Delaware, 1998.