1 / 10

Introduction to Digital Logic: Truth Tables & Comparator Concepts

Learn about digital logic concepts such as truth tables and comparators in this brief preface to laboratory exercises. Understand how electronic elements process digital information and key terms like fan-out and propagation delay.

cade-blanchard
Télécharger la présentation

Introduction to Digital Logic: Truth Tables & Comparator Concepts

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Digital Logic Topics Brief notes to preface the laboratory exercise BAE 5413

  2. Truth Tables • Consider the following and gate • A truth table “enumerates” the output state for every possible input state. See Example: Input Output A B C 0 0 0 1 0 0 0 1 0 1 1 1 BAE 5413

  3. Comparator • Vout = +5 if Vin 1 > Vin 2 else Vout = 0 • Devices are available designed for the comparison purpose. They are in general faster and better suited for this purpose than a conventional op-amp. BAE 5413

  4. Digital logic • Electronic elements for processing digital (numeric) information • Normally bi-state, 1 or 0 digital values represented by two discrete electrical signals • Our concern is primarily interfacing with logic inputs and outputs • Important terms/issues • Fan-out - the amount of output drive capacity compared to input drive requirement • Open collector - an output that is configured as a switch to reference voltage rather than a voltage level signal • Propagation delay - the amount of time between a change in input state and a change in output state. BAE 5413

  5. Common logic types (families) • TTL • Transistor-Transistor Logic - Classically has 0 and 5 V nominal logic levels. 3V logic is evolving • Signal levels Output Input BAE 5413

  6. http://www.interfacebus.com/voltage_threshold.html BAE 5413

  7. http://www.interfacebus.com/voltage_threshold.html BAE 5413

  8. BAE 5413

  9. TTL • Gate Electronic structure Conventional Bipolar Gate Open Collector Gate BAE 5413

  10. CMOS Logic • CMOS - Logic • Low power • 3 - 18 V logic levels • Static Sensitive • Gate Structure BAE 5413

More Related