Overview
This lecture discusses the necessity of analog systems despite advances in digital technology, and outlines the process of converting real-world analog signals to digital form for processing. It introduces the course focus on digital circuit building blocks, including combinational and sequential circuits.
Need for Analog Systems
- All real-world (real-time) signals are analog in nature.
- Entirely ignoring analog systems is not possible because input signals from the environment are analog.
- Analog signals may be weak (e.g., satellite data) and require amplification and filtering before further processing.
Analog to Digital Conversion Process
- Analog signals are pre-processed by amplifying and filtering to improve quality.
- An Analog-to-Digital Converter (ADC) converts the analog signal to a digital form.
- Digital processing can then be performed using computers (e.g., mapping weather data).
- For display or physical output, a Digital-to-Analog Converter (DAC) turns processed digital data back into an analog signal (like light on a screen).
Prevalence and Limitations of Digital Systems
- Most modern systems are predominantly digital (90-95%), with a small analog portion (5-10%).
- Digital systems are favored due to cost and flexibility, but analog roles remain essential.
- Digital systems are inherently slower due to the need for conversion steps (analog-digital-analog).
Course Focus: Digital Circuit Building Blocks
- The course covers basic components that make up digital circuits and systems.
- Emphasis on understanding how blocks function, their inputs and outputs, and design methods.
- Students will learn to design digital systems to meet specific requirements.
- The course will differentiate between combinational and sequential circuits.
Key Terms & Definitions
- Analog Signal — A continuous signal representing real-world information (e.g., sound, temperature).
- Digital Signal — A discrete (binary) representation of information suitable for computer processing.
- Transducer — A device that converts real-world physical signals into electrical analog signals.
- ADC (Analog-to-Digital Converter) — Converts analog signals into digital form.
- DAC (Digital-to-Analog Converter) — Converts digital signals back to analog form.
- Combinational Circuit — Digital circuit where output depends only on current inputs.
- Sequential Circuit — Digital circuit where output depends on current inputs and previous states.
Action Items / Next Steps
- Prepare to study the building blocks of digital circuits.
- Review the difference between analog and digital signals.
- Get familiar with the concepts of ADC and DAC.