ADC Conversion Time Comparison: Flash, SAR, Ramp & Dual-Slope ADC ADC Conversion Time: Flash, Digital Ramp, SAR and Dual-Slope ADC Analog-to-digital converters (ADCs) convert continuous analog signals into digital values. Different ADC architectures require different amounts of time to complete this conversion. This guide explains the working principles, conversion-time formulas, and differences between Flash, Digital Ramp, Successive Approximation, and Dual-Slope ADCs. Table of Contents Flash ADC conversion time Digital Ramp ADC conversion time Successive Approximation ADC conversion time Dual-Slope ADC conversion time ADC conv...

Dual-Slope ADC Given C = 0.1 µF R = 100 kΩ V ref = 2 V V o = 10 V Integrator Equation For an integrator: V o = V ref t / RC Therefore: t = V o RC / V ref Calculate RC RC = (100 × 10 3 ) (0.1 × 10 −6 ) = 0.01 s Calculate Conversion Time t = 10(0.01) / 2 t = 0.05 s = 50 ms Therefore, t = 50 ms . Answer: B (50 ms) Browse All Solved Papers (2012 - 2025) → UGC-NET : Electronics Science Study Material (Subject: 088) → Further Reading: GATE EC Previous Year Papers with Solutions

  ADC Types Comparison ADC Types Comparison An Analog-to-Digital Converter (ADC) converts an analog voltage into a digital number. Main ADC types: Flash ADC Successive Approximation (SAR) ADC Dual-Slope ADC Sigma-Delta ADC 1. Flash ADC Concept Flash ADC compares the input voltage with many reference voltages simultaneously. It is the fastest ADC architecture. Block Diagram Input → Comparator Array → Encoder → Digital Output Comparator Formula Comparators = 2ⁿ - 1 Example for 3-bit ADC: 2³ - 1 = 7 comparators Reference Voltages 0.5V, 1.0V, 1.5V, 2.0V, 2.5V, 3.0V, 3.5V Input Example Vin = 2.3V Thermometer code: 1111000 Binary output: 100 Speed Conversion Time ≈ 1 clock cycle Advantages ...

Dual Slope ADC Dual Slope A/D Converter Definition A dual slope ADC converts an analog signal into digital form using integration and timing. Working Principle 1. Integration Phase The input voltage is applied to an integrator for a fixed time, causing a steady change in output. 2. De-integration Phase A reference voltage is applied in reverse, and the time taken for the output to return to zero is measured. Result: This time is proportional to the input voltage. Summary High accuracy Excellent noise rejection Slower operation speed Applications Digital voltmeters Measurement instruments Precision systems

Percentage Resolution of a DAC The resolution of a Digital-to-Analog Converter (DAC) is the smallest change in output voltage corresponding to a one-bit change in the digital input. Resolution Formula Resolution = 1 / (2 n − 1) Where: n = number of bits of the DAC Percentage Resolution Percentage Resolution = (1 / (2 n − 1)) × 100 % Full-Scale Range Calculation The full-scale output voltage of a DAC depends on the reference voltage. Step Size (Resolution Voltage) = V ref / (2 n − 1) Full Scale Output = (2 n − 1) / 2 n × V ref Example (8-bit DAC) Number of bits (n) = 8 2 8 = 256 Percentage Resolution = (1 / 255) × 100 = 0.392 % If Vref = 5V: Step Size = 5 / 255 = 0.0196 V Common DAC Percentage Resolutions DAC Bits Percentage Resolution 4-bit 6.67% 8-bit 0.392% 10-bit 0.098% 12-bit 0.0244% Return to Main Page → Why do we use ...

ADC SNR Gain Why the ADC SNR Formula is 6.02N + 1.76 dB The full-scale quantization noise model assumes: The quantization step is Δ = 2V FS / 2 N Quantization noise is uniformly distributed from -Δ/2 to +Δ/2 1. Quantization Noise Power A uniform noise distribution over width Δ has variance: σ² = Δ² / 12 2. Signal Power (Full-Scale Sine Wave) The RMS value of a sine wave with peak amplitude V FS is: V rms = V FS / √2 Signal power: P s = V FS ² / 2 3. SNR Calculation Using SNR = P s / P q , and substituting the expressions for signal and noise: SNR = 3 · 2 2N 4. Convert SNR to dB SNR dB = 10log(3) + 20N log(2) Using constants: log₁₀(2) = 0.3010 → 20 log(2) = 6.02 dB 10 log(3) = 4.77 dB After RMS correction for sine vs. square wave (−3.01 dB), the final expression becomes: SNR ADC = 6.02N + 1.76 dB This is the standard “ideal ADC SNR” formula.   1. ADC SNR Gain (Resolution-Based SNR Gain) Inc...