---
title: "Why digitize analog signals"
subject: "Instrumentation II"
chapter: 4
key: "semester_5/instrumentation_ii:why-digitize"
source: https://www.bctengineer.com/q/semester_5/instrumentation_ii/why-digitize
site: BCT Engineering
---

# Why digitize analog signals

Instrumentation II · Chapter 4: Interfacing A/D And D/A Converters

- Asked in: 2073 Chaitra, 1 marks; 2073 Shrawan, 2 marks (asked 2 times)
- Video: [Introduction to ADC and DAC](https://www.youtube.com/watch?v=HicZcgdGxZY) — ALL ABOUT ELECTRONICS
- Answer checked by Claude Sonnet 5.5 on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_5/instrumentation_ii/why-digitize
- Whole chapter: https://www.bctengineer.com/md/semester_5/instrumentation_ii/chapter-4

## Question

Why analog signals need to be transferred to digital?

## Short answer

Analog signals are digitized to allow processing by microprocessors/DSPs, provide noise immunity, enable accurate long‑distance transmission and storage with error correction, simplify digital display and logging, permit programmability for calibration and control, and facilitate multiplexing of many channels.

## Answer

Analog signals are converted to digital form because:

1. **Processing by a digital system:** microprocessors, computers and DSPs work only on binary numbers, so measurement, calculation, linearisation, filtering and control can be done by software.
2. **Noise immunity:** a digital signal has only two levels, so noise does not change the value as long as it is below the threshold; analog signals degrade with every stage and cable.
3. **Accurate storage and transmission:** data can be stored in memory and sent over long distances with error detection and correction without loss of quality.
4. **Display and logging:** digital values are easily shown on LCD/LED, logged and printed.
5. **Flexibility and accuracy:** calibration, scaling and decisions can be changed by program, and accuracy depends on the number of bits.
6. **Multiplexing and integration:** many channels can be shared on one converter and connected to networks.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Why more noise immune?
   A. More amplification
   B. Only two levels, noise below threshold doesn't change value
   C. Higher voltage
   D. Analog is better
   Answer: B. Digital values survive noise. (Key point: Noise)

2. Why convert for processing?
   A. Analog is faster
   B. Lower power
   C. Needs less memory
   D. Microprocessors work only on binary numbers
   Answer: D. Digital systems need binary. (Key point: Processing)

3. Benefit for transmission?
   A. Lower bit rate
   B. No wires
   C. Louder
   D. Error detection and correction without quality loss
   Answer: D. Digital data can be checked and corrected. (Key point: Storage)

## Related in Instrumentation II

- [Digital transmission system; analog vs digital](https://www.bctengineer.com/question.md?key=semester_5%2Finstrumentation_ii%3Aanalog-digital-transmission-compare) — Instrumentation II, chapter 5
- [Analog and digital communication systems](https://www.bctengineer.com/question.md?key=semester_5%2Finstrumentation_ii%3Aanalog-digital-comm-systems) — Instrumentation II, chapter 5
- [Advantages of digital over analog transmission](https://www.bctengineer.com/question.md?key=semester_5%2Finstrumentation_ii%3Adigital-vs-analog-transmission-adv) — Instrumentation II, chapter 5

## Related in other subjects

- [Difference between analog and digital signals](https://www.bctengineer.com/question.md?key=semester_3%2Fdigital_logic%3Aanalog-vs-digital-signals) — Digital Logic, chapter 1
- [Advantages of digital over analog signals](https://www.bctengineer.com/question.md?key=semester_3%2Fdigital_logic%3Adigital-over-analog-advantages) — Digital Logic, chapter 1, asked 5×
- [Analog/digital signals and digital advantages](https://www.bctengineer.com/question.md?key=semester_3%2Fdigital_logic%3Adefine-analog-digital-advantages) — Digital Logic, chapter 1, asked 5×
- [Define analog and digital signals](https://www.bctengineer.com/question.md?key=semester_5%2Fdata_communication%3Aanalog-digital-signal-define) — Data Communication, chapter 1