---
title: "Characteristics of ADC and DAC"
subject: "Instrumentation II"
chapter: 4
key: "semester_5/instrumentation_ii:adc-dac-characteristics"
source: https://www.bctengineer.com/q/semester_5/instrumentation_ii/adc-dac-characteristics
site: BCT Engineering
---

# Characteristics of ADC and DAC

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

- Asked in: 2073 Shrawan, 4 marks; 2071 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/adc-dac-characteristics
- Whole chapter: https://www.bctengineer.com/md/semester_5/instrumentation_ii/chapter-4

## Question

What are the characteristics of ADC and DAC?

## Short answer

ADC characteristics: resolution, full‑scale range, conversion time, quantisation error (±½ LSB), offset/gain errors, INL, DNL, input type, aperture jitter. DAC characteristics: resolution, full‑scale output, settling time, offset/gain errors, INL, DNL (monotonicity), glitch energy, and output type.

## Answer

#### Characteristics of ADC
1. **Resolution:** n bits give 2^n codes; LSB = FSR / 2^n. For example 8 bits and 5 V: 19.5 mV.
2. **Full scale range (FSR)** and reference voltage.
3. **Conversion time:** time from start of conversion to valid output; sets maximum sampling rate.
4. **Quantisation error:** +/-1/2 LSB.
5. **Accuracy and linearity:** offset, gain, INL, DNL; missing codes.
6. **Input type:** unipolar or bipolar, input impedance, number of channels.
7. **Output:** binary, offset binary, BCD; latched, tri-state; control signals SOC, EOC, OE.
8. **Aperture time and jitter,** SNR, ENOB.

#### Characteristics of DAC
1. **Resolution:** smallest output step = FSR / (2^n - 1).
2. **Full-scale output** and reference voltage; unipolar/bipolar.
3. **Settling time:** time for the output to settle within 1/2 LSB after a code change.
4. **Accuracy,** gain error, offset error and temperature coefficient.
5. **Linearity (INL), differential nonlinearity (DNL) and monotonicity.**
6. **Glitch energy** and slew rate.
7. **Input:** parallel/serial digital word, input latches, logic compatibility.
8. **Output:** voltage or current, output impedance.
9. **Power supply rejection ratio,** power consumption.

Example: a 10-bit DAC with 5 V reference has a resolution of 5 / 1023 = 4.89 mV per step.

## Check yourself

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

1. LSB of 8-bit ADC at 5 V?
   A. 5 mV
   B. 19.5 mV
   C. 39 mV
   D. 4.88 mV
   Answer: B. 5/256 = 19.5 mV. (Key point: ADC resolution)

2. Settling time of DAC is?
   A. Start time
   B. Time to settle within 1/2 LSB after code change
   C. Conversion time
   D. Aperture
   Answer: B. Limits speed. (Key point: Settling)

3. Control signals of ADC?
   A. SOC, EOC, OE
   B. ALE, RD
   C. CS, WR only
   D. HOLD, HLDA
   Answer: A. Start of conversion, end of conversion, output enable. (Key point: Control signals)

## Related in Instrumentation II

- [Errors in ADC and DAC](https://www.bctengineer.com/question.md?key=semester_5%2Finstrumentation_ii%3Aadc-dac-errors) — Instrumentation II, chapter 4, asked 7×
- [DNL and INL errors in ADC and DAC](https://www.bctengineer.com/question.md?key=semester_5%2Finstrumentation_ii%3Adnl-inl) — Instrumentation II, chapter 4, asked 2×

## Related in other subjects

- [Counter-type ADC numerical (VFS = 12 V)](https://www.bctengineer.com/question.md?key=semester_4%2Fadvanced_electronics%3Acounter-adc-12v-numerical) — Advanced Electronics, chapter 3
- [Dual slope ADC block diagram; integral linearity](https://www.bctengineer.com/question.md?key=semester_4%2Fadvanced_electronics%3Adual-slope-integral-linearity) — Advanced Electronics, chapter 3