Which ADC architecture is known for very high speed but tends to have higher power consumption?

• A. Flash
• B. SAR
• C. Sigma-Delta
• D. Dual Slope

Answer: (A)

Speed versus power in ADC architectures is the key idea here. Flash ADCs achieve very high speeds because they compare the input against a full set of reference levels in parallel with a large bank of comparators, so the conversion completes in a single step. That parallelism is what makes them blazing fast, but it also means many active components run continuously and the resistor ladder and comparators consume significant power, leading to higher power consumption and larger silicon area. SAR converters use a single comparator and a capacitor DAC to perform a binary search, which is slower but far more power-efficient. Sigma-Delta emphasizes high resolution through oversampling and digital filtering, which adds latency and isn’t aimed at the absolute highest speed. Dual Slope focuses on excellent noise rejection and precision at low speeds. So the architecture known for very high speed but higher power consumption is the Flash design.