Contents:
SECTION 1-- BASIC TRANSISTOR-TRANSISTOR LOGIC: Digital Families-Series 54/74 Circuits-The Basic Gate- NOR Gates-Inverters-AND-OR-INVERT Gates-Open-Collector and Wired-OR Circuits-Expandable Gates-Loading Rules- Noise Immunity
SECTION 2-- FLIP-FLOPS: Set- Reset Flip-Flops-NoR-Gate Flip- Flops- Clocked Flip Flops-TTL Flip- Flops-Other Versions
SECTION 3-- DECODERS: One- of- Four Decoder-One-Out-of-Ten Decoder-Seven-Segment Decoders-Lamp Test and Ripple Blanking
SECTION 4-- MULTIPLEXERS: Data Selectors- Multiple Data Input-Multiple Load Input
SECTION 5--SHIFT REGISTERS: Eight-Bit Shift Register-Serial- Parallel Shift Register- Left-Shift and Right- Shift Registers
SECTION 6-- COUNTERS: Four-Bit Binary Counters-Divide-by-Twelve Counters-Decade Counter-Up/Down Binary Counter-Up/Down Decade Counter
SECTION 7-- ARITHMETIC CIRCUITS: Adders-True Complement Circuit-Comparator
SECTION 8-- PARITY AND PRIORITY: Parity Generator-Priority Encoder
SECTION 9-- MEMORIES: Random-Access Memory ( RAM)-Register File-Read-Only Memory ( ROM)-Content Addressable Memory
SECTION 10-- SPECIAL CIRCUITS: Interface Driver-One-Shot Multivibrator-Latches
SECTION 11-- INCREASING TTL SPEED AND DEVICE DENSITY: Propagation Time-High-Speed TTL-Low-Power TTL-Active Bypass TTL-Schottky-Clamped TTL-Low-Power Schottky TTL-Tri-State Logic-TTL Trends-Families of TTL
SECTION 12-- TTL APPLICATION: Up/Down Counting System-Data Transmission System
SUB-SECTION A-- DIGITAL LOGIC CONVENTIONS
SUB-SECTION B-- NUMBERING SYSTEMS
SUB-SECTION C-- TTL POWER SUPPLY
SUB-SECTION D-- GUIDELINES FOR SYSTEM DESIGN
SUB-SECTION E-- GLOSSARY
This guide is written to provide the reader with the background knowledge needed to understand the operation of integrated circuit devices. With a good understanding of the basic devices, it is possible to work with the logic systems that perform digital functions.
SECTION 1 discusses the digital families of which transistor-transistor logic, or TTL, is a part. It also covers the basic units--the gate, the various basic circuits, and the voltage and current requirements. The next five SECTIONs discuss the different types of circuits used in a logic system, while SECTION 7 explains the mathematics used in TTL. SECTIONs 8 and 9 examine the devices and methods used to determine information priority and storage. SECTION 10 discusses how TTL logic can be joined to other type circuits and logic families.
The final SECTIONs are concerned with how fast TTL logic will operate, how many individual units can be combined in a single IC package, and how basic counting and data transmission systems work. Appendices and a glossary are provided to further understanding of gates, flip-flops, counters, logic numbering, and power systems.
A design engineer or service technician, needing an understanding of the internal and external circuit construction of logic devices, will find the information in this guide an invaluable aid.
ABOUT THE AUTHOR
GF has a Bachelor of Science degree in Electrical Engineering from the University of Missouri, and has worked extensively in the design of automatic control circuits and systems.
He has written articles for numerous publications.
He is a contributing editor to Electronic Engineering Times and has served on the editorial staffs of electronics magazines.
Preface
The use of digital logic devices probably started with industrial control systems and telephone networks, where relays were used to perform logic or switching. Long before that, of course, the abacus was used for purely mathematical operations.
With the parallel development of electronic digital computers and semiconductor technology, digital logic devices really began to stand out. Circuit designers took a new look at how to do things. Soon digital instruments and complex systems began to appear: digital voltmeters, frequency counters, sophisticated control systems for military aircraft, special-purpose digital computers, and control systems for complex weapons and space probes. Finally, we have digital wrist watches, and this will not be the end of the line.
Underlying the end products are the semiconductor logic devices that perform the digital functions of signal generation, counting, adding, subtracting, multiplying, shifting, encoding, decoding, remembering or storing, multiplexing, comparing, etc. The first group of semiconductor circuits developed to per form the basic digital functions became known as Resistor Transistor Logic, or RTL. Hardly was RTL well launched when Diode-Transistor Logic, or DTL, appeared. Then, DTL under went a major modification and evolved into Transistor-Transistor Logic-TTL. TTL, today, is the dominant form of semiconductor logic.
Numerous families of TTL devices exist; some are compatible with other TTL and DTL families, and some are not. Most major semiconductor manufacturers-in the United States, Europe, and Asia-make devices in one or more of the major TTL families. The basic circuits all work the same, and the functions performed are identical. However, differences do exist, particularly in power consumption, operating speeds and voltages, pin-numbering and arrangement, and physical shapes and sizes. In addition, circuit designs at the chip level may vary from manufacturer to manufacturer. These differences do not, in general, affect the operation of the circuit and do not change the block diagrams (which show how the devices work) . Today, as integrated circuit technology sweeps over electronics, more and more TTL functions are being combined on one chip. New TTL devices appear frequently. A vast amount of excellent literature has been published to explain how the various devices can be used to do many things, from frequency synthesis, to data communications, to computer design. However, before you can work at the system level, you need a good under standing of the basic devices: gates, flip-flops, counters, shift registers, etc. This guide attempts to provide that understanding.
I would like to thank the semiconductor manufacturers for their aid in the preparation of this guide. They have helped me directly, through personal contact during the past few years, and indirectly, through published information and data. I particularly wish to thank Texas Instruments Incorporated, Fair child Semiconductor, Motorola Semiconductor Products Incorporated, National Semiconductor, Signetics Corporation, and Teledyne Semiconductor.
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